IC-NRLF 


LIBRARY 


UNIVERSITY  OF  CALIFORNIA. 


OK 


Mrs.  SARAH  P.  WALS WORTH. 

Received  October,  1894. 
Accessions  A/b.^/2/7...      Class  No._^ 


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*  .  I.'** 

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MANUAL 


MINERALOGY  AND  GEOLOGY. 


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MANUAL, 


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MINERALOGY  AND  GEOLOGY 


EBENEZER  EMMONS,  M.  D. 

LECTURER  ON  CHEMISTRY  AND  NATURAL  HISTORY  IN  WILLIAMS  tfftlXEGE. 


SECOND  EDITION. 


-  : 


ALBANY: 

WEBSTER  AND  SKINNERS. 
1832. 


Entered  according  to  Act  ofVtitiffTw1te$edr  1#32,  by  WEBSTER  and 
SKINNERS,  in  die  C/erA:'5  Q^ce  o/  the  District  Court  for  the  Northern 
District  of  the  State  of  New-York. 


'  «     /£33k 


PREFACE 


TO   THE    SECOND    EDITION. 


A  new  edition  of  the  following  work  having  been  call- 
ed for,  the  author  has  been  induced  to  remodel  it,  by  the 
conviction  that  a  method  of  teaching  and  studying  the 
science  different  from,  and  superior  to,  that  which  had  for- 
merly been  pursued  in  this  country,  ought  to  be  adopted. 
That  method  is  well  known  to  have  possessed  too  much 
of  a  traditionary  character,  and  to  have  obliged  the  stu- 
dent to  depend  more  upon  the  ipse  dixit  of  his  instructor 
than  his  own  investigation.  In  preparing  this  edition  it 
has  been  the  design  of  the  author,  so  far  as  it  was  in  his 
power,  to  furnish  the  student  with  a  guide  by  means  of 
which  he  might  be  satisfactorily  conducted  through  the 
process  of  examining  minerals,  to  the  attainment  of  cor- 
rect results.  To  accomplish  this,  sufficient  information 
is  given  in  the  following  pages,  to  enable  him  rightly  to 
employ  the  characters  of  mineral  substances  and  to  trace 
the  relations  existing  between  them.  . 

To  make  this  simple,  and  at  the 'same  time  scientific, 
the  classification  of  Prof.  Mohs  has  been  adopted,  with  his 
method  of  treating  the  principal  heads  under  which  a 
Natural-Historical  system  is  to  be  developed.  In  treating 
of  Crystalography,  however,  it  has  been  deemed  proper 
still  to  follow  the  system  of  Brooke,  as  the  abstruse  man- 
ner in  which  Mohs  has  taught  it,  (requiring  a  knowledge 
of  the  higher  mathematics,)  would  here  preclude  its  gen- 
eral use. 

The  author  considers  the  classification  of  Mohs  in  its 
leading  features,  as  perfect  as  the  present  state  of  the  sci- 

* 


IV  PREFACE. 

ence  will  admit,  and  he  entertains  no  doubt  but  that  the 
student  will  ultimately  adopt  the  same  opinion.  To  test 
its  advantages,  he  is  advised  to  exercise  himself  in  carry- 
ing known  minerals  through  the  different  classes  and  or- 
^  ders  ;  he  will  thus  also  acquire  a  confidence  in  the  prac- 
tical part  of  the  science,  and  be  fully  prepared  to  enter 
into  the  investigation  of  unknown  substances.  He,  how- 
ever, who  wishes  to  obtain  a  knowledge  of  the  Mineral 
Kingdom,  must  make  himself  familiar  with  Terminology, 
as  it  in  fact  contains  the  rudiments  of  the  science,  and  is 
the  groundwork  of  the  whole.  If  he  neglects  this,  he 
may  be  assured  that  all  his  investigations  will  be  uncer- 
tain and  unsatisfactory,  and  lead  to  no  well  determined 
results. 

To  illustrate  the  crystaline  forms,  a  few  figures  have 
been  introduced ;  and  although  a  greater  number  might 
have  been  employed  with  advantage,  it  is  hoped  that 
they  will  be  sufficient  to  give  the  student  general  and 
correct  ideas  of  the  relations  existing  between  the  prima- 
ry and  secondary  forms.  In  the  course  of  the  work,  it 
will  be  found  that  occasionally  where  the  figure  is  not 
given,  the  dimensions  of  forms  are  referred  to.  The 
mode  of  expression  in  these  cases  is  explained  by  stating 
that  crystalographers  employ  certain  letters  to  designate 
the  different  planes,  angles  and  edges  of  crystals.  Thus 
the  letters,  P  M  T,  always  refer  to  the  primary  faces  or 
planes  of  a  crystal ;  the  vowels,  A  E  I  O,  are  used  to 
denote  the  solid  angles ;  and  the  consonants,  B  C  D  F 
G  H,  the  primary  edges.  They  are  arranged  in  the  or- 
dinary mode  of  writing,  beginning  at  the  upper  part  of 
the  figure  and  proceeding  from  left  to  right.  When  the 
planes,  &c.  are  similar,  the  same  letter  is  made  use  of, 

** 


PREFACE.  V 

and  they  are  distinguished  from  each  other  by  adding 
the  mark  '  or  "  to  the  letter  employed.  For  example, 
in  figure  10,  the  letter  P  stands  upon  the  terminal  plane, 
and  the  letter  M  on  the  lateral  planes  ;  this  is  intended 
to  show,  that  whilst  the  terminal  and  lateral  planes  are 
dissimilar,  the  lateral  ones  are  similar  to  each  other.  In 
figure  11,  the  letters,  P  M  T5  being  made  use  of,  shew 
that  the  planes  are  dissimilar,  whilst  A  A  and  E  E,  being 
placed  upon  the  solid  angles,  shew  that  those  designated 
by  the  same  letter  are  similar,  and  those  by  different  let- 
ters dissimilar. 

In  compiling  the  description  of  a  species,  it  is  very 
important  to  express  the  properties  of  the  collective  indi- 
viduals composing  it.  The  description  of  an  individual, 
however  accurate  and  full,  would  not  convey  a  notion  of 
the  species,  but  only  of  a  single  variety.  While,  there- 
fore, we  abandon  the  description  of  each  individual  va- 
riety, we  should  at  the  same  time  avoid  giving  it  a  dis- 
tinct epithet  or  name.  This  practice  has  already  retarded 
the  advance  of  the  science,  and  should  be  discounten- 
anced. 

Some  errors  have  unavoidably  escaped  correction, 
owing  as  well  to  the  indisposition  of  the  author,  as  to  the 
distance  of  his  residence  from  the  place  of  publication. 
They  are,  however,  it  is  hoped,  all  noticed  in  the  errata, 
and  are  such  as  may  generally  be  corrected  with  the  pen. 

E.  EMMONS. 

Williamstown,  August,  1832. 


TABLE  OF  CONTENTS. 


INTRODUCTION. 

§    1  The  mineral  kingdom,     .     .   .H^.". 

§   2  Advantages  of  a  knowledge  of  the  mineral 

kingdom,     .         .        .     W>"       • 
§    3.  Design  of  mineralogy,    ....        2 
§    4.  Heads  under  which  a  system  of  mineralogy 

is  to  be  developed, 

§    5.  Terminology,         .... 
§    6.  Theory  of  the  system,     .      ,  *.      . 
§   7.  Nomenclature,       ,      -^      v        . 
§    8.  Characteristic,       I  -  '"•«•""•    r 
§    9.  Physiography,        .      VJF    -vV\;V- 
§  10.  Objects  which  mineralogy  considers, 
§  11.  Method  of  obtaining  a  knowledge  of  mine- 
ralogy, '••  •;'••        -  !•.    .       ^          .V 

§  12.  Natural-historical  properties,        .»  4 

§  13.  Division  of  the  natural-historical  properties, .    4 

PART  i.     Terminology. 

§  14,  Regular  forms,      '.  "    ". '"!     .        *        .        5 
§15.  Limits  of  crystals,          •        *      "       '«'J-      5 


§  16.  Edges, 

§  17.  Angles,        ,.      '  .  • 
§  18.  Solid  angle,  .      ;. 
«^  19.  Value  of  angles,    . 
^  20.  Similar  planes, 
<§  21.  Similar  edges, 
§  22.  Similar  angles, 
§  23.  Similar  solid  angles, 


Considerations  arising  from  the  different  Forms  which 

different  Minerals  assume. 

§24.  Primary  and  secondary  forms,        *.*  ,   •        6 
§  25.  Number  and  kinds  of  primary  forms,        .        6 


X  CONTENTS. 

-  §26.  Cube,  .        .        .    te*s*rv  ••**•*       ,  7 

§  27.  Tetrahedron,         .       ,.        ;        .      ./.  7 

§28.  Regular  octahedron,       .     ;  ;w    V       •  8 

§  29.  Rhombic  dodecahedron,         >        .        .  8 

§  30.  Octahedron  with  a  square  base,      .  8 

§  31.  Octahedron  with  a  rectangular  base,        .  9 

§  32.  Octahedron  with  a  rhombic  base,     .         .  9 

§  33.  The  right  square  prism,          .      v  &'.'"•  10 

§34.  Rectangular  prism,        «•$     .        .         .  10 

§  35.  The  right  rhombic  prism,         .         .     1 ! .  10 

§36.  The  right  oblique-angled  prism,   f  Jst  ;  •  ,  "H 

§37.  The  oblique  rhombic  prism,     .         .      •  .  11 

§38.  The  doubly  oblique  prism,       .        .      , •  .'.  12 

§  39.  The  rhombohedron,  or  rhomboid,      .         .  12 

§  40.  The  regular  hexagonal  prism,          .         .  13 

Relations  subsisting  between  Primary  and  Secondary  Forms. 

§41.  Secondary  forms,  .      :(»>?     .  «fr>  >  '.&•>      ..  13 
§  42.  Transformation  of  primary  into  secondary 

forms,     +^~  ^iV    .'. . ,  14 
§43.  Molecules,  ...  >  <^iv: :^(* .-•.'*    /  £l  i  ^  16 

§44.  Kinds  of  molecules,       -.   i^r*,;      ^i      .  16 

§  45.  Formation  of  crystals  from  molecules,     .  17 

'§46.  Of  decrements,      ;;       .        .        .     f..  18 

§47.  Simple  decrement,        J». ,      .        .     \  .  18 

§  48.  Mixed  decrement,                   .         .     "j  .  18 

§49.  Intermediary  decrements,        .        *?  £  •  ^ 
§  50.  The  effect  of  decrement  on  edges  or  angles 

is  regulated  by  symmetrical  laws,       .  19 
§  51.  Imperfections  of  crystals, 

§  52.  Structure  and  cleavage,          .     i    , '      •  20 

§53.  Direction  of  cleavage,    .        .     .   *;,'.%•  20 

§54.  Cleavage  of  similar  planes,     •        I        «  20 

§55.  Nomenclature  of  cleavage,      .       ".'      .  21 

§  56.  Goniometer,          .        .    » ;  i  ^  :  ..        ^  21 

§  57.  Determination  of  primary  forms,      .       ^  21 

§  58.  Fracture,     .     &&  \     .    %&••'     ,        ,  33 


CONTENTS.  XI 

SEC.  n.     The  Natural-Historical  Properties  of  Compound 
Minerals. 

§59.  Surface,       .         .,-*    ....  22 

§  60.  Regular  composition,    ....  22 

§  61.  Irregular  composition,    ....  23 

§  62.  Imitative  shapes,  ....      '.  23 
§  63.  Imitative  shapes  arising  out  of  the  geodes  of 

crystals,  ...        .        •      ,  .  23 

§64.  Amorphous  compositions,       .         .      ;..  24 

§  65.  Accidental  imitative  shapes,    .         .       \.  24 

§66.  Particles  of  composition,         ...  24 

§  67.  Structure  of  compound  minerals,      .        .  25 

SEC.  in.     Considerations  of  the  Properties  which  belong  both 

to  Simple  and  Compound  Bodies. 
§68.  Division, ''.-.25 

Of  the  Optical  Properties  of  Minerals. 

§  69.  Colour,  lustre  and  transparency,     .      ;-  .  25 

§70.  Colour  and  streak,          .         .     .'  ,"|.*'i  '•••  25 

§71.  Division  of  colours,        .        .       ,;M •-.,  ;.  26 

§  72.  Metallic  colours,    .        .      ;;i*.,     i&jji  26 

§  73.  Non-metallic  colours,     .         .  : ,.  26 

§  74.  Peculiarities  in  the  occurrences  of  colours,  26 

§75.  The  streak,        '  .^      .         .      ...^  •     .  27 

§  76.  Degrees  of  transparency,         .         .         .  27 

§77.  Lustre,         .         .        .     '   .        .     y.  27 

Of  the  Physical  Properties  of  Minerals, 

§  78.  Explanation,          ,         ....       29 

§  79.  State  of  aggregation,      . '  .         .29 

§  80.  Hardness,     ....         .         .       29 

§  81.  Specific  gravity,     .         .     *  .         .        .30 

§52.  Magnetism, 30 

§83.  Electricity,    .         .         .        .         •        .      30 

§84.  Taste, 30 

§  85.  Odor,  .         .         .         .         .     '    .        .30 
.§86.  Chemical  character,       ....      31 


xii  CONTENTS. 

PART  ir.     Theory  of  the  System. 

§  87.  Identity,       ,'^     .    ^  *        .        ?     j «  31 

§88.  Difference,-    .        .     :;.:.        ,,,...    --,  31 

$  89..  Species,        .        .    |;  ./  ;V' .    .' ."_'•  V  31 

§90.  Genus,          .        .        .     -:..*',;  1V-C    .  32 

§91.  Order,           .        .        .     ',  '4 .'  'v  V>V     .  32 

§92.  Class,        -,-^v     ,        .        .     ^.,4..     .  33 

PART  in.    Nomenclature. 

§  93.  Definition,    '.  '•  '  f .      ~  ;V^     .             *  4  33 

§  94.  Object  of  the  names,       .       ^>-^  ^M  '*  33 

§  95.  Name  of  the  order,        .        .     '  - .  ^  •>  34 
^  96.  Selection  and  signification  of  the  names  of 

the  orders,        .       ,  •  •       .         .        .  34 

§97.  Name  of  the  genus,      ,.  .      *.       .        .  34 

§98.  Denomination  of  the  species,           .        .  34 
§  99.  Trivial  nomenclature,     .                         .34 

PART  iv.     Characteristic. 

§100.  Definition,  .        ^    -  .;!  ,-t  v:'^.^*   *'  ^ 

§  101.  Properties  of  the  characters,          .        .  35 
4  102.  Absolute  and  conditional  characteristic 

marks,    ^;.     ,;u  '?.•       .      i..;i.     .'*  35 

§  103.  Base  of  a  perfect  characteristic,     .     !>  35 

§  104.  Use  of  the  characteristic,    ;>. ; ,            %  35 

PART  v.     Physiography. 

§  105.  Definition,          -,   |:~V       .               ';»  35 

§106.  Objects  of  physiography,    _  .     ;*  ;*'  >;  36 

x  §  107.  General  description  of  the  species,         .  36 

§  108.  Arrangement  of  the  general  descriptions,  36 
§  109.  The  collective  descriptions  do  not  depend 

on  the  systems,        .        .       .        .  36 


INTRODUCTION. 


§  1.  The  Mineral  Kingdom. 

The  mineral  kingdom  embraces  those  natural  produc- 
tions which  are  unorganized.  . 

Natural  productions  are  obviously  difisifyle.ipk)  two  greq,t 
classes,  organized  and  unorganized.  Tha-difleMictjs  between 
these  are  so  plain,  that  a  mere  glanc-3  at  them  w,iU  l?e  .s.ufji-, 
cient  for  our  purpose.  Organized  "bpdi'es,  ^rejeonjip^R'e^  tif. 
different  parts  and  organs,  and  each  organ  performs  a  distinct' 
function.  The  power  which  controls  the  organs  is  a  vital 
power,  and  is  commonly  termed  VITAL  AFFINITY.  Organized 
bodies  increase  in  size  by  the  assimilation  of  matter  to  the  in- 
ternal parts.  They  cease  to  grow  and  naturally  or  necessa- 
rily die  ;  and  the  particles  which  compose  them  being  no  lon- 
ger under  the  control  of  vital  affinity,  are  separated  and  form 
new  combinations,  which  are  not  organized.  On  the  other 
hand,  in  unorganized  bodies,  the  particles  composing  their 
parts  are  homogeneous ;  the  power  which  unites  them  is 
physical  attraction  :  they  increase  in  size,  not  by  the  assimi- 
lation of  matter,  but  by  the  apposition  of  similar  particles  to 
their  external  surfaces  :  they  do  not  necessarily  cease  to 
exist. 

Organized  bodies  may  be  distinguished  into  animals  and 
vegetables.  These  are  properly  denominated  the  Animal  and 
Vegetable  Kingdoms.  No  such  distinction  can,  from  the  na- 
ture of  the  bodies  composing  it,  be  made  in  the  Mineral  King- 
dom. A  proposed  division,  viz. :  that  of  bodies  into  atmos- 
pherilia  and  fossils,  cannot  be  considered  as  philosophical, 
since  it  respects  merely  the  state  of  bodies  as  they  are  gase- 
ous or  solid,  and  hence  it  has  not  received  the  approbation  of 
a  majority  of  naturalists.  Besides,  the  term  fossil  is  applied 
to  the  remains  of  organized  bodies  found  in  the  earth. 

§  2.   Advantages  of  a  Knowledge  of  the  Mineral 
Kingdom. 

Experience  has  already  taught  us  that  a  knowledge  of  the 
mineral  bodies  is  important  in  the  arts ;    the  more  perfect 
our  knowledge  is,  the  more  extensive  will  be  their  application 
1 


2  INTRODUCTION. 

to  useful  purposes.  Besides  it  is  rational  and  wise  to  study 
the  properties  of  bodies  aside  from  their  immediate  applica- 
tion to  the  arts,  since  they  illustrate  those  interesting  laws 
which  produce  regular  forms  and  structure,  and  exhibit  elec- 
trical, magnetical  and  optical  properties,  not  only  interesting 
in  themselves,  but  which  may  be  useful  in  explaining  other 
phenomena  in  the  great  field  of  nature. 

§  3.  Design  of  Mineralogy. 


\  Mineralogy  loe^iers  the  inorganic  productions  as  they 
&£«3:  and  riot  how  they  have  been  formed. 

-  .The.  inquiry  hew'  -natural  productions  have  been  formed, 
4»es.*  riot-  come  lAtt&J  "the  province  of  natural  history.  The 
restricting  of  the  design  of  mineralogy  to  the  consideration  of 
the  natural  historical  properties,  will  serve  to  promote  greatly 
the  real  interests  of  science,  as  it  will  not  involve  the  study  of 
principles  foreign  to  this  department  of  knowledge. 

§  4.  Heads  under  which  a  System  of  Mineralogy  is  to  be 
developed. 

Natural  history  in  general,  and  mineralogy  in  particu- 
lar, is  developed  under  the  following  heads.  1.  Termin- 
ology. 2.  Theory  of  the  system.  3.  Nomenclature. 
4.  Characteristic.  5.  Physiography. 

§  5.  Terminology. 

Terminology  explains  those  natural  properties  which 
are    employed  in  .recognizing    and    describing    natural 
irlies. 


bodies. 


6.  Theory  of  the  System. 


Theory  of  the  system  fixes  the  principles  of  classifica- 
tion. It  contains  the  reasoning  or  philosophical  part  of 
the  subject. 

§  7.  Nomenclature. 

Nomenclature  furnishes  the  names  of  natural  produc- 
tions, and  explains  the  principles  by  which  those  names 
are  selected. 


INTRODUCTION.  S 

$  8.  Characteristic. 

The  characteristic  teaches  the  use  of  the  natural  proper- 
ties in  such  a  way  that  the  student  may  be  led  to  the 
name  which  -any  natural  production  has  received. 

§  9.  Physiography. 

Physiography  teaches  the  arrangement  of  those  marks 
or  properties  by  which  natural  bodies  are  distinguished, 
in  a  way  best  calculated  to  impress  the  mind  with  an 
image  of  the  object  described. 

§10.   Objects  which  Mineralogy  considers. 

The  objects  which  mineralogy  considers  are  Individ- 
uals. 

An  individual  in  the  mineral  kingdom  is  a  single  body.  It 
may  exist  in  an  isolated  state,  or  in  connection  with  others. 
A  crystal  of  quartz,  garnet  or  diamond  is  an  individual*  It  is 
common,  however,  for  individuals  to  be  connected  together. 
Examples  of  individuals  in  this  state  are  furnished  in  masses  of 
granular  limestone,  granular  quartz,  &c.  the  particles  of  which 
they  are  composed  are  individuals.  An  individual  is  also  a 
simple  mineral,  but  in  a  sense  different  from  that  which  is  un- 
derstood in  chemistry;  the  term  being  used  to  distinguish 
simple  from  compound  minerals  ;  the  latter  embracing  those 
masses  in  which  we  can  discover  two  or  more  individuals  of 
the  same  kind.  The  term  mixed  mineral  is  used  to  designate 
compound  masses  which  contain  two  or  more  individuals  of 
different  kinds,  as  granite,  mica  slate,  &c. 

§11.  Method  of  obtaining  a  Knowledge  of  Mineralogy. 

The  student  may  acquire  a  knowledge  of  the  mineral  king- 
dom by  making  himself  acquainted  with  the  natural  proper- 
ties of  inorganic  bodies,  and  the  terms  which  are  used  in  de- 
scribing them.  He  ought  to  commence  at  once  by  collecting 
every  thing  within  his  reach,  if  he  has  not  access  to  a  cabinet, 
and  apply  to  them  the  characteristic.  This  process,  so  far  as 
other  sciences  are  concerned,  requires  some  knowledge  of 
the  elements  of  geometry.  The  first  object  is,  to  become  famil- 
iar with  a  majority  of  the  species  in  the  natural  system,  after 
which  the  more  interesting  study,  the  '*  affinities  of  inorganic 
bodies,"  may  be  pursued  with  profit  and  great  satisfaction. 


4  INTRODUCTION. 

§  12.  Natural  Historical  Properties. 

They  are  those  properties  which  nature  has  conferred 
on  inorganic  bodies,  and  which  are  invariable  during  the 
natural  state  of  the  body. 

Those  properties  which  are  observed,  in  consequence  of 
some  change  which  lias  been  wrought  upon  the  substance,  or 
which  it  has  suffered  from  exposure  to  the  elements,  are  unfit 
to  be  used  in  the  determination  of  mineral  bodies;  they  are 
therefore  excluded  from  occupying  a  place  in  the  characteris- 
tic. Those  properties  are  treated  of  in  other  branches  of 
science,  which,  in  respect  to  their  principles,  differ  entirely 
from  those  of  natural  history. 

§13.  Division  of  the  Natural-Historical  Properties. 

The  natural-historical  properties  of  minerals  are  con- 
sidered under  three  heads.  1.  Such  as  relate  to  simple 
minerals,  §  10.  2.  Such  as  relate  to  compound  minerals. 
3.  Such  as  are  common  to  both. 

The  natural-historical  properties  are  their  colour,  lustre, 
hardness,  specific  gravity,  form,  structure,  &c.  They  include 
the  greater  part  of  the  characters  which  are  called  external 
characters.  These  characters  will  be  considered  in  the  fol- 
lowing order :  First.  Such  as  relate  to  the  individual  itself* 
or  a  fragment  of  the  individual :  they  are  such  as  relate  to 
space,  or  the  form  it  has  received,  the  structure,  surface,  and 
the  effect  which  it  produces  on  light,  so  far  as  regularity  of 
form  is  concerned.  Second.  Those  characters  which  belong 
to  compound  minerals,  as  their  composition,  the  forms  of  com- 
pound minerals,  and  the  mode  of  junction  of  individuals. 
third.  Those  characters  will  be  considered  which  are  com- 
mon both  to  simple  and  compound  minerals,  as  colour,  lustre, 
transparency,  hardness,  state  of  aggregation,  £c. 

The  principles  of  Terminology  will,  therefore,  be  considered 
in  three  sections. 


INTRODUCTION,  5 

TERMINOLOGY. 
PART  I. 

PROPERTIES   WHICH   BELONG    TO   SIMPLE   MINERALS. 
SECTION  I. 

§  14  Regular  Forms. 

In  mineralogy  a  regular  form  is  termed  a  crystal.  It 
consists  of  continuous  and  homogeneous  matter,  and  oc- 
cupies a  regular  space. 

The  science  which  treats  of  regular  forms  or  crystals  is 
termed  crystalography  ;  it  has  for  its  object  the  determina- 
tion of  the  form  and  dimensions  of  crystaline  bodies,  with  a 
view  to  discover  the  differences  which  exist  among  them. 

§  15.  Limits  of  Crystals. 

Crystals  are  limited  by  regular  surfaces,  which  are 
termed  their  planes  or  faces. 

The  planes  or  faces  appear  under  different  shapes  and  re- 
ceive certain  names  according  to  these  shapes  :  thus,  some 
are  triangular,  others  rhombic,  &c.  and  are  termed  tri- 
angular faces,  rhombic  faces  respectively.  Faces  may  not  be 
perfectly  plane  'and  smooth,  yet  in  crystalography  they  are 
considered  as  perfect  planes. 

§  16.  Edges. 

The  lines  which  are  formed  by  the  meeting  of  planes 
are  termed  edges- 

§  17  Angles. 
The  meeting  of  two-edges  forms  a  plane  angle. 

§  18.  Solid  Angle. 

A  solid  angle  is  formed  by  the  meeting  of  three  or 
more  edges  or  lines. 

§  19.   Value  of  Angles » 

The  value  or  measure  of  angles  is  the  number  of  de- 
grees and  minutes  of  which  they  consist. 

1* 


CF-  INTRODUCTION. 

§  20.  Similar  Planes. 

The  planes  of  crystals  are  similar  when  their  corres- 
ponding edges  are  proportional  and  their  corresponding 
angles  are  equal. 

§  21.  Similar  Edges. 

Edges  are  similar  when  they  are  produced  by  the  meet- 
ing of  planes  respectively  similar,  at  equal  angles. 

§  22»  Similar  Angles. 

Angles  are  similar  when  they  are  equal  and  contained 
within  similar  edges,  respectively. 

§  23.  Similar  Solid  Angles. 

Solid  angles  are  similar  when  they  are  formed  of  an 
equal  number  of  plane  angles,  of  which  the  corresponding 
ones  are  similar. 

The  student  should  be  informed  that  there  are  some  irregu- 
larities in  crystals  in  the  length  of  their  edges  and  the  dimen- 
sions of  their  faces.  Some  faces  are  more  extended  than  oth- 
ers, their  similarity  is  then  infered  from  their  situation.  Irreg- 
ularities in  the  length  of  edges  and  the  extension  effaces,  are 
not  noticed  in  crystalography  as  they  are  accidental  variations, 

CONSIDERATIONS    ARISING    FROM    THE    DIFFERENT    FORMS 
WHICH    DIFFERENT    MINERALS    ASSUME. 

§  24.  Primary  and  Secondary  Forms. 

Of  the  different  forms  which  crystaline  bodies  assume 
or  under  which  they  appear,  some  one  is  selected  as  the 
primary  form,  the  remainder  of  the  forms  of  the  same 
species  are  called  secondary  forms. 

The  primary  form  is  the  parent  or  original  form,  from  which 
all  the  secondary  forms  are  supposed  to  arise,  from  certain 
symmetrical  changes  which  the  primary  has  undergone,  and 
these  changes  are  supposed  to  take  place  according  to  certain 
lawa,  being  based  upon  the  relations  which  are  observed  to 
exist  among  the  different  forms  of  the  same  mineral  species. 

^  25.  Number  and  Kinds  of  Primary  Forms.* 
There  are  fifteen  primary  forms.     1.  The  Cube.     2 

»See  Note  A. 


INTRODUCTION. 


The  regular  Tetrahedron.  3.  The  regular  Octahedron. 
4.  Rhombic  Dodecahedron.  5.  The  Octahedron  with  a 
square  base.  6.  Octahedron  with  a  rectangular  base. 
7.  Octahedron  with  a  rhombic  base.  8.  The  right  square 
Prism.  9.  The  right  rectangular  Prism.  10,  The  right 
rhombic  Prism.  11.  The  right  oblique  angled  Prism. 
12.  The  oblique  rhombic  Prism.  13.  The  doubly  ob- 
lique Prism.  14.  The  Rhombohedron  or  Rhomboid.  15. 
The  regular  hexahedral  Prism. 

The  primary  form  will  be  observed  under  different  circum- 
stances. Sometimes  a  mineral  appears  under  the  primary 
form  without  any  modification  of  its  edges  or  angles  ;  in  other 
instances  the  primary  is  entirely  concealed  under  the  seconda- 
ry faces  of  the  crystal  and  must  be  developed  by  cleavage,  or 
its  form  infered  from  the  known  relations  which  exist  between 
the  primary  and  secondary  forms  of  crystaline  bodies.  The 
primary  is  never  an  imaginary  form. 


Fig.  1. 


§26.   Cube. 

The  cube  (Fig.  1.)  is  a  solid  con- 
tained under  six  square  faces. 

The  angles  of  the  cube  are  right  an- 
gles. From  the  perfect  symmetry  of 
its  form  the  cube  has  a  similar  axis*  in 
four  directions,  which  pass  through  the 
centre  of  each  pair  of  solid  angles. 

27.  Tetrahedron. 


The  regular  tetrahedron  (Fig.  2.) 
is  a  solid  contained  within  four  equi- 
lateral triangular  planes. 

The  inclination  of  its  planes  as  P  on 
F  700  31'  and  43".  Its  plane  angles 
60°.  It  possesses  a  similar  axis  in 
four  directions. 


*  An  axis  of  a  crystal  is  an  imaginary  line  passing  through  the  solid,  and 
through  two  opposite  solid  angles.   See  (Fig,  3.)  the  line  a  b  represents  an 


Fig.  2. 


INTRODUCTION. 


§  28.  Regular  Octahedron. 

The  regular  octahedron  (Fig.  3.)  is  a 
solid,  bounded  by  eight  equilateral  trian- 
gles, or  it  is  formed  of  two  four  sided  py- 
ramids united  base  to  base,  which  base  is  a 
square. 

The  plane  angles  of  the  regular  octahedron  60°.    The  in- 
clination of  their  facea  as  P  on  F  or  P"  109°  28'  16". 


§  29..  Rhombic  Dodecahedron. 


Fig.  4. 


The  rhombic  dodecahedron  (Fig.  4)  is 
contained  within  twelve  equal  rhombic 
faces,  having  six  solid  angles,  consisting 
each  of  four  acute  plane  angles,  the  op- 
posite ones  as,  a  b,  being  sometimes  call- 
ed the  summits,  and  eight  solid  angles, 
consisting  each  of  three  obtuse  plane  angles. 

The  mutual  inclination  of  two  adjacent  faces  on  each  other, 
as  P  on  P"  120°.  Its  planer  angles  109°  28'  16"  and  70° 
31'  43". 

This  solid  has  two  dissimilar  sets  of  axis  which  pass  through 
its  centre.  One  set  passes  through  the  acute  solid  angles  as 
the  angles  a  b,  the  other  as  c  d  pass  through  the  obtuse  solid 
angles. 


§  30.  Octahedron  with  a  Square  Base. 


The  octahedron  with  a  square  base 
(Fig.  5.)  is  a  solid  bounded  by  light 
isosceles  triangular  planes ;  the  bases 
of  the  triangles  constitute  the  edges 
of  the  base  of  the  octahedron. 

When  the  angles  at  the  summits  as 
a  b,  measure  less  than  60°  the  octahe- 
dron is  called  acute.  When  the  same 
angles  are  greater  than  60°  the  octahe- 
dron is  obtuse. 


Fig.  5. 


INTRODUCTION, 


9 


This  form  may  present  a  great  variety  of  angles,  and  the  in- 
dividuals will  differ  from  each  other  in  the  inclination  of  P  on 
P"andofPonP'. 

The  square  base  distinguishes  this  solid  from  the  two  suc- 
ceeding forms,  and  the  isosceles  triangular  faces  distinguish 
it  from  the  regular  octahedron. 

§31.   Octahedron  with  a  Rectangular  Base. 

Fig.  6. 

•Fig.  6,  is  an  octahedron  with' a 
rectangular  base.  The  planes  are 
isosceles  triangles  but  unequal. 

In  this  form  the  broad  planes  P  P', 
meet  at  the  edge  of  the  base  at  a  more 
obtuse  angle  than  the  narrow  planes 
M  M'.  The  edge  D  is  therefore  the 
obtuse  edge,  and  the  meeting  of  the 
planes  M  M'  the  acute  edge  of  the 
base.  The  individuals  belonging  to  this  class  of  forms  will 
differ  from  each  other  in  the  inclination  of  P  on  P'  or  of  M  oh 
M'. 


§  32.   Octahedron  with  a  Rhombic  Base. 


The  octahedron  with  a  rhombic  base 
(Fig.  7.)  is  contained  within  eight 
equal  scalene  triangular  planes. 

This  form  is  in  position  when  the  great- 
er diagonal  of  the  base  is  horizontal,  hence 
the  planes  which  meet  in  the  edge  B  form 
a  more  acute  angle  than  those  which 
meet  in  C,  the  former  is  therefore  denomi- 
nated the  acute  and  the  latter  the  obtuse 
edge  of  the  pyramid,  The  solid  angle  at 
E  is  the  acute  lateral  solid  angle,  and  that 
at  I  the  obtuse  lateral  solid  angle.  The 


Fig.  7. 


individuals  of  this 


class  will  differ  from  each  other  in  the  inclination  of  P  on  P' 
and  on  P". 


10 


INTRODUCTION. 


§  33.  The  Right  Square  Prism. 

The  right  square  prism  (Fig.  8.)  is 
a  quadrilateral  solid  whose  edges  B 
and  G  are  unequal. 

The  bases  of  this  class  of  forms  are 
square  and  the  lateral  faces  equal  rectan- 
gles. The  form  would  be  a  cube  if  the 
edges  B  and  G  were  equal.  The  indir 
viduals  will  differ  from  each  other  in  the  comparative  length  of 
the  edges  B  and  G. 

§  34.  Rectangular  Prism. 


Fig.  8. 
B 

P           ^ 

B 

G 

^ 

MG 

M 
^ 

The  right  rectangular  prism 
(Fig.  9.)  is  a  quadrilateral  solid, 
whose  bases  are  equal  rectangles, 
and  whose  edges  C  G  and  B  are 
unequal. 

Individuals  of  this  class  of  forms 
differ  from  each  other  in  the  com- 
parative length  of  the  edges  C  G  and  B. 

The  right  square  and  right  rectangular  prisms  have  the 
same  axis  as  the  cube,  besides  which,  they  have  an  imaginary 
line  passing  through  the  centres  of  their  bases  which  is  called 
a  prismatic  axis. 


B  ^- 

Fig.  9. 
c 

f*3 

P      ^ 

| 

C 

B 

I 

M 

T 

§  35.  The  Right  Rhombic  Prism. 


Fig.  10. 


The  rigJiC  rhombic  prism 
(Fig.  10.)  is  a  quadrilateral  sol- 
id, whose  bases  are  equal  rhombs 
and  whose  lateral  planes  are  ei- 
ther equal  squares  or  equal  rect- 
angles. 

The  solid  angles  A  are  the  ob- 
tuse and  those  at  E  the  acute  solid 
angles.  The  edge  G  is  the  acute  and  H  the  obtuse  lateral 
edges.  The  individuals  of  this  class  will  differ  from  each  oth- 
er in  the  inclination  of  M  on  M',  or  in  the  ratio  of  the  edge  H 
to  the  edge  B. 


INTRODUCTION. 


11 


§  36.  The  Eight  Oblique-Angled  Prism 

The  right  oblique-angled 
prism,  (Fig.  11.)  is  a  quadri- 
lateral solid,  whose  bases  are 
oblique-angled  parallelograms, 
and  whose  adjacent  lateral 
planes  are  unequal,  one  of 
which  must  be  rectangular,  the 
other  may  be  either  a  square 
or  rectangle. 

The  angles  and  edges  of  this  class  are  denominated  as  in 
the  right  rhombic  prism. 

The  individuals  of  this  class  will  differ  from  each  other  in 
the  inclination  of  M  on  T,  and  on ;  the  relative  lengths  of  the 
edges,  C,  B  and  H. 

§  37.  The  Oblique- Ehombic  Prism. 

Fig.  12. 

The  oblique  rhombic-prism,  (Fig. 
12.)  is  a  quadrilateral  solid,  whose 
bases  are  rhombs,  and  whose  late- 
ral planes  are  ecjual  oblique-angled 
parallelograms. 

The  figure  is  supposed  to  be  ob- 
lique in  the  direction  of  O  A,  so  that 
the  terminal  plane  P  forms  an  obtuse 
angle  with  the  edge  H.  The  planes 
M  and  M/  may  meet  at  an  acute  or  an 
obtuse*  angle.  The  solid  angle  at 
A  will,  in  either  case,  be  called  the  acute  solid  angle  ;  that  at 
O  the  obtuse  solid  angle  ;  and  those  at  E  the  lateral  solid  an- 
gles. 

The  edges  B  are  the  acute  terminal  edges  ;  those  atD  the 
obtuse  terminal  edges.  The  edge  H  and  its  opposite  are  the 
oblique  edges  of  the  prism,  and  G  and  its  opposite  the  lateral 
edges  of  the  prism.  The  individuals  of  this  class  will  differ 
in  the  inclination  of  M  on  M',  and  in  the  ratio  of  the  edge  H 
to  the  edgeD. 

*  When  the  planes  M  M'  meet  at  an  acute  angle,  the  prism  is  said 
to  be  oblique  from  an  acute  edge.  When  they  meet  at  an  obtuse  angle, 
they  are  said  to  be  oblique  from  an  obtuse  edge. 


INTRODUCTION. 


The  oblique-rhombic  prism  has  a  greater  and  lesser,  and 
two  transverse  axes,  besides  a  prismatic  axis.  The  first 
passes  through  the  acute  solid  angles,  the  second  passes 
through  the  obtuse  solid  angles,  and  the  two  transverse  pass 
through  the  lateral  solid  angles. 


§  38.  The  Doubly  Oblique  Prism. 


Fig.  13. 


The  doubly  oblique  prism,  (Fig. 
13.)  is  a  quadrilateral  solid,  whose  B 
bases  and  whose  lateral  planes 
are  generally  oblique-angled  par- 
allelograms. The  only  equality 
which  subsists  is  between  the  op- 
posite and  parallel  planes. 


This  class  of  prisms  differ  from 
the  oblique  rhombic  prisms  in  the  angles  A,  E,  I  and  O, 
which  are  dissimilar,  and  also  in  the  acute  terminal  angles  B, 
C,  and  obtuse  terminal  edges  D,  F. 

The  edges  and  angles  of  this  class  are  designated  by  the 
same  terms  as  have  been  used  for  the  corresponding  ones  of 
the  oblique  rhombic  prism.  The  figure  is  supposed  to  stand 
oblique  in  the  direction  O  A,  so  that  the  terminal  plane  forms 
an  obtuse  angle  with  the  edge  H. 

The  doubly  oblique  prism  has  four  unequal  axes  passing 
through  the  pairs  of  opposite  solid  angles,  and  also  a  prismatic 
axis,  which  inclines  from  a  perpendicular. 

Individuals  belonging  to  this  class  will  differ  from  each 
other  in  the  inclination  of  P  on  M,  P  on  T,  and  M  on  T,  also 
in  the  ratios  of  the  edges  D,  H,  F. 

§  39.   The  Rhombohedron,  or  Rhomboid. 

The  rhombohedron  (14)  is  a  solid  con- 
tained within  six  equal  rhombic  planes, 
having  two  of  its  solid  angles  composed 
of  three  equal  plane  angles,  which  are. 
sometimes  called  the  summits. 

The  angle  A  is  the  superior,  and  O  the 
inferior  angle  of  the  plane  P  ;  those  at  E 
are  the  lateral  angles  ;  the  edges  B  the  su- 
perior, and  those  at  D  the  inferior  lateral 
edges.  The  solid  angle  at  A  is  called  the 
summit. 


Fig.  14. 


INTRODUCTION.  13 

The  individuals  of  this  class  differ  from  each  other  in  the 
inclination  of  P  on  P' ;  when  P  on  P'  measures  more  than  90° 
the  rhomboid  is  obtuse  ;  when  less,  it  is  acute. 

The  angle  P  on  P'  is  limited  between  180°  and  60°,  but  can 
never  reach  those  limits,  for  the  planes  P  P7  would  become 
one  plane,  and  its  axis  would  vanish  ;  or  in  other  words,  be- 
come infinite,  and  the  figure  would  cease  to  be  a  rhomboid. 

§  40.   The  Regular  Hexagonal  Prism. 

The  regular  hexagonal  prism, 
(Fig.  15.)  is  a  solid  whose  bases 
are  regular  hexagons,  and  whose 
lateral  planes  are  parallelograms. 

The  adjacent  planes  M  M'  incline 
on  each  other  at  an  angle  of  120°. 

The  prism  has  as  many  axes  as  it  has  opposite  solid  angles, 
but  the  line  generally  regarded  as  the  axis  passes  through  the 
centre  of  the  bases. 

The  only  difference  which  will  exist  between  individuals  of 
this  class  will  be  in  the  ratio  of  the  edge  G  to  the  edge  B. 

(For  remarks  on  Isomorphism,  see  Note  I.) 

RELATIONS    SUBSISTING    BETWEEN    PRIMARY   AND    SECONDARY 
FORMS. 

§  41.  Secondary  Forms. 

The  secondary  forms  are  those  which  are  produced  by 
modifications,  which  take  place  either  on  the  solid  angles 
or  edges  of  the  primary  forms. 

Whenever  a  plane  appears  in  the  place  of  an  edge  or  angle 
which  does  not  belong  to  the  primary  form,  the  edge  or  angle 
suffers  a  modification,  which  is  called  a  replacement.  It  is 
scarcely  necessary  to  say  that  a  replacement  is  something  dif- 
ferent from  a  change  in  the  dimensions  of  a  form.  .The  latter 
can  have  no  effect  to  alter  the  shape  of  a  solid.  The  seconda- 
ry forms,  therefore,  embrace  all  those  varieties  of  form  which 
differ  in  any  respect  from  the  primary,  and  though  they  are  nu- 
merous and  complicated,  yet  they  are  capable  of  being  reduced 
to  a  few  classes,  and  become  intelligible  to  most  students. 


14 


INTRODUCTION. 


Fig.  17. 


Fig.  18. 


§  42.  Transformation  of  Primary  into  Secondary  Forms. 

Forms  may  be  conceived  to  pass  into  each  other  by  the 
replacement  of  the  edges  or  solid  angles. 

Fig.  16. 

The  change  spoken  of  in  the  proposition  may  be 
understood  by  reference  to  Fig.  16,  the  general 
form  of  which  is  a  cube ;  the  triangular  planes 
which  appear  in  the  place  of  the  solid  angles  modi-  1^  )\^/ 
fy  but  slightly  the  original  square  faces  of  the 
cube.  If  these  planes  should  be  enlarged  by  any 
cause,  the  square  faces  would  disappear,  either 
wholly  or  in  part,  and  the  form  of  the  cube  would 
pass  jnto  the  regular  octahedron ;  (Fig.  17.)  a  re- 
sult which  may  be  verified  by  shaving  down  cubi- 
cal pieces  of  wax,  or  any  soft  substance. 

Again,  the  small  quadrangular  planes  which 
appear  in  place  of  the  solid  angles  of  the  reg- 
ular octahedron,  ( Fig.  18,)  if  enlarged  until 
the  original  faces  of  the  octahedron  disappear, 
would  transform  it  into  the  cube. 

Other  forms  may  be  conceived  to  be  pro- 
duced in   the  same   manner :   thus,   if  the 
regular  octahedron  (Fig.  19.)  has  its  edges 
replaced  by  tangent*  planes,  the  figure  will 
be   bounded   by   twenty  planes,  eight  of 
which  are  triangular  and  twelve  hexahedral. 
If  the  latter  are  enlarged  until  the  triangu- 
lar or  primary  faces  disappear,  the  rhombic 
dodecahedron  will  be  produced.    .  The  in- 
clination of  the  planes  e  on  P  or  P'  144° 
44'  6". 

Again,  the  rhombic  dodecahedron  may  be 
transposed  into  the  octahedron,  by  remov- 
ing the  obtuse  solid  angles,  §  30,  and  en- 
larging them  until  the  other  faces  disappear. 

Or,  the  cube  will  be  the  result  of  a 
modification  of  the  rhombic  dodecahedron, 
by  replacing  the  acute  solid^  angles  by  tan- 
gent planes,  as  may  be  shown  by  inspect- 
ing Fig.  20. 


Fig.  19. 


Fig.  20. 


*  A  tangent  plane  inclines  equally  on  the  adjacent  planes. 


INTRODUCTION.    ' 


15 


Or,supposing  the  cube  to  be  the  primary 
form,  the  rhombic  dodecahedron  will  result 
from  tangent  planes,  when  applied  to  the 
edges  of  the  cube,  which  is  illustrated  by 
Figs.  20  and  21.  The  inclination  of  the 
plane  c  on  P  or  P'= 


Fig.  21. 


P 

f 

{/• 

If  the  edges  of  the  cube,  (Fig.  22.)  are 
replaced  by  two  planes,  a  series  of  four- 
sided  pyramids  will  be  produced.  The 
planes  of  the  cube  on  the  one  side  and  those 
of  the  rhombic  dodecahedron  on  the  other 
side,  will  evidently  limit  this  series  of 
figures. 

The  following  remarks  will  serve  to  illustrate  summarily 
what  is  taught  by  the  figures  belonging  to  this  section.  1. 
The  replacement  of  the  twelve  edges  of  the  cube  and  of  the 
regular  octahedron  by  tangent  planes,  produce  the  Dodeca- 
hedron. 2.  The  replacement  by  tangent  planes  of  eight  solid 
angles  of  the  cube,  or  the  eight  obtuse  angles  of  the  dodeca- 
hedron, produce  the  regular  Octahedron.  3.  The  replacement 
of  the  six  acute  solid  angles  of  the  dodecahedron,  (aud  it  may 
be  added  though  the  figure  is  not  given,)  the  six  edges  of  the 
tetrahedron  by  tangent  planes,  produce  the  Cube. 

The  student^  will  meet  with  numerous  examples  of  the 
above  transitions  among  minerals.  Thus  fluor,  the  sulphurets 
of  lead,  silver  and  zinc,  diamond,  red  oxide  of  copper,  &c., 
are  found  crystalized  under  the  forms  of  the  cube,  octahedron 
and  rhombic  dodecahedron ;  and,  as  has  been  shown,  those, 
solids  are  transformed  into  each  other  by  tangent  planes,  ap- 
plied either  to  the  edges  or  solid  angles. 

The  following  are  instances  of  transformation  by  unequal 
inclination  of  the  secondary  on  the  primary  planes. 
Thus  if  the  cube  suffers  a  replacement  or,  trun- 
cation of  its  edges  by  single  planes,  inclining 
unequally  on  the  primary,  a  solid  will  be  produced 
which  is  bounded  by  twelve  pentagonal  faces. 
(Fig.  2-3.) 


Tig.  23. 


16  INTRODUCTION. 

Fig,24. 

Another  solid  which  is  frequently  met 
with  among  crystals  is  produced  from 
the  cube  by  the  replacement  of  its  solid 
angles  by  three  planes,  resting  on  the 
primary  planes.  The  new  form  is  de- 
nominated the  Trapezoedron,  and  is 
contained  under  twenty-four  trapezoidal 
planes. 

§  43.  Molecules. 

The  minute  particles  of  which  crystals  are  composed 
are  called  molecules.  They  are  homogeneous,  symmet- 
rical, solid  particles,  and  contained  within  plane  surfaces, 

The  term  molecule,  or  which  is  synonymous,  integrant  par- 
ticle, is  to  be  distinguished  from  the  elementary  particle  of 
chemists.  The  former  are  the  smallest  particles  of  any  body 
which  can  exist  without  decomposition ;  the  latter  are  the 
elements  which  combine  together  to  form  the  particle.  For  in- 
stance, the  carbonic  acid  and  lime,  which  together  form  lime- 
stone, are  the  elementary  particles,  the  single  atom  which 
their  union  produces  is  a  molecule  or  integrant  particle. 

§  44.  Kinds*  of  Molecules. 

The  different  classes  of  Primary  forms  are  supposed  to 
be  formed  of  molecules  of  different  kinds,  so  arranged  as 
to  fill  all  the  vacuities  and  occupy  the  least  space. 

There  are  seven  kinds  of  molecules  which  enter  into  the 
structure  of  the  different  classes  of  primary  forms  :  they  are 
conveniently  exhibited  at  one  view  in  the  following  table. 

The  cube ] 

regular  tetrahedron  .  .  lmolecule  a  cube. 

octahedron   .  .  f 

rhombic  dodecahedron,  j 

all  quadrangular  prisms.. .molecules  similar  prisms. 

*  The  late  Dr.  Wollsston  (Phil.  Trans.  1813,)  has  proposed  to  consider  the 
primitive  particles  or  molecules  as  spheres,  or  oblate  or  oblong  spheroids. 
This  ingenious  theory  explains  very  satisfactorily  the  structure  of  the  different 
classes  of  regular  solids,  as  it  is  very  easy  to  understand  the  production  of 
cubes,  octahedrons,  tetrahedrons,  &c.  on  the  supposition  that  these  ultimate 
particles  are  spherical.  The  student  is  advisea  to  verify  the  hypothesis  by- 
arranging  a  series  of  balls  so  as  to  produce  the  different  primary  forms. 


INTRODUCTION.                                   17 

octahedron 

with  a  square  base.  ] 

'  molecule  a 
J    square  prism. 

Proportion- 
al in  dimen- 
sions to  the 

—  rectangular  base.  ] 

>  molecule  a  rect- 
J    angular  prism. 

edges  of  the 
base  and  to 
'the  axis  of 
each  partic- 

vV»/-\w\Ki /•»      Hoc?** 

>  molecule  a 
J    rhombic  prism. 

ular  octahe- 
dron res- 
pectively. 

rhomboid  or  rhombohedron molecule  a  similar  solid. 

,  7  molecule  an  equilateral 

hexagonal  prism £      triangular  prism. 

It  is  scarcely  necessary  to  remark,  that  the  molecules  of 
bodies  are  infinitely  small  in  relation  to  our  senses  ;  hence  the 
view  which  is  taken  of  them  is  to  be  considered  as  theoretical, 
and  it  is  necessary  to  divest  ourselves  of  notions  which  would 
make  them  real,  from  the  absolute  manner  in  which  they 
are  spoken  of.  By  their  assistance,  however,  we  are  enabled 
to  demonstrate  the  relations  between  primary  and  secondary 
forms,  and  to  understand  the  manner  in  which  the  edges  and 
solid  angles  of  crystals  may  be  replaced  or  suffer  modification. 

§  45.  Formation  of  Crystals  from  Molecules. 

Fig.  25. 

Crystals  are  supposed  to  commence 
their  formation  by  the  aggregations 
of  a  few  homogeneous  molecules 
which  constitute  the  primary  form, 
which  on  farther  increase  in  size 
may  suffer  an  abstraction  of  rows  of 
molecules  either  from  the  edges  or 
solid  angles. 

If  we  suppose  that  the  first  mole- 
cules are  arranged  in  the  form  of  a 
plate,  and  their  successive  plates  of  the 
same  size  to  be  formed  upon  each  oth- 
er, it  is  evident  no  alteration  in  the 
shape  of  the  plate  will  ensue  ;  it  will 
merely  increase  in  size.  If,  however,  after  two  or  three  plates 
were  brought  together,  each  succeeding  deposit  should  be 
diminished  on  one  side  by  a  single  row  of  particles,  it  is  evi- 
dent that  in  the  place  of  an  edge  a  plane  would  appear,  and  if 
these  abstractions  should  take  place  all  round  the  solid,  the 

3* 


•^. 

I    36         Y 

1£ 

4 

c—  _ 

v! 

c^. 

F3 

7 

18  INTRODUCTION. 

area  of  the  surface  would  constantly  diminish  until  a  pyramid 
was  formed,  which  would  terminate  in  a  single  molecule  or 
point  In  Fig.  25,  the  pyramid  is  incomplete,  a  portion  of 
the  primary  plane  remains  on  which  the  letter  P  is  placed. 

§  46.    Of  Decrements. 

The  term  decrement  is  used  to  express  the  omitted 
rows  of  molecules  spoken  of  in  §45. 

§  47.  Simple  Decrement. 

A  simple  decrement  is  said  to  take  place  when  any 
number  of  rows  of  molecules  are  omitted,  belonging  to 
plates  of  two  or  more  molecules  in  thickness,  either  on 
the  edges  or  angles  of  primary  forms. 

§  48.  Mixed  Decrement. 

A  mixed  decrement  is  said  to  take  place  when  unequal 
numbers  of  molecules  in  height  and  breadth  are  omitted, 
neither  of  the  members  being  multiples  of  the  other,  such 
as  three  in  height  and  two  in  breadth,  or  four  in  breadth 
and  three  in  height. 

§  49.  Intermediary  Decrements. 
Intermediary  decrements  may  be  conceived  to  take 
place  when  rows  of  compound  molecules  are  abstracted 
from  successively  superimposed  plates,  each  compound 
molecule  containing  unequal  numbers  of  single  rows  in 
length ,  breadth  and  heighth. 

The  effect  of  decrement  is  always  to  produce  a  plane.  When 
the  decrement  is  on  a  solid  angle  and  an  equal  number  of  mole- 
cules are  abstracted  on  each-side  of  the  angle,  a  tangent  plane 
is  formed,  and  the  direction  will  be  parallel  to  the  diagonal  of 
the  plane  on  which  the  new  plane  rests. 

Intermediary  decrements  always  affect  the  angles,  but  the 
direction  in  which  they  proceed  is  never  parallel  to  a  diagonal 
or  an  edge.  It  is  evident  that  the  inclination  of  the  secondary 
planes  produced  by  decrement  is  increased  or  diminished  by 
the  number  of  omitted  rows  either  in  height*  or  breadth,  for  in- 
stance, the  inclination  of  a  plane  produced  by  the  abstraction 
of  a  single  row  of  molecules  from  an  edge  will  be  greater  than 

*Decrement  in  height  relates  to  the  thickness  of  the  plate,  and  decrement  ia 
breadth  to  the  width  of  the  plate  from  which  molecules  are  abstracted. 


INTRODUCTION. 


19 


Fig,  27. 


if  two  rows  were  subtracted  in  breadth ;  if  a  row  of  molecules 
of  the  thickness  of  two  plates  is  subtracted  and  only  one  in 
breadth,  the  inclination  will  be  greater  than  in  the  first  in- 
stance mentioned,  and  a  pyramid  which  is  formed  by  this  de- 
crement would  be  acute,  but  by  the  second  instance  given  it 
would  be  obtuse  or  a  low  pyramid. 

§  50.   The  effect  of  Decrement  on  edges  or  angles  is  regu- 
lated by  Symmetrical  Laws. 

Fig.  26. 

Decrements,  or  in  other  words  replace- 
ments, take  place  on  the  similar  edges  or 
angles  of  primary  forms. 

When  a  solid  angle  of  the  cube  is  replac- 
ed, all  the  angles  are  similarly  affected,  as 
is  represented  in  Fig.  26. 

The  modification  of  the  rectangular  prism 
(Fig.  27.)  represents  a  decrement  on  the 
similar  edges. 

The  replacements  which  are  exhibited 
in  Figs.  18,  19,  20,  21,  22,  are  instances 
which  conform  to  the  law  expressed  in  the 
proposition  at  the  head  of  this  paragraph. 

The  above  law  is  not  however  universal. 
Boracite  and  Tourmaline  are  instances  of  exceptions  to  it :  in 
the  latter  mineral,  the  planes  which  are  formed  at  the  extremi- 
ties of  the  prism  are  dissimilar,  whereas,  if  the  law  of  symme- 
try had  operated,  they  would  have  been  similar  planes. 

§  51.  Imperfections  of  Crystals.. 
Crystals  frequently  exhibit  irregularities  in  their  exter- 
nal forms,  which  may  arise  from  contact  with  other  bod- 
ies, or  from  a  disturbance  of  the  molecular  attraction  dur 
ing  their  formation. 

Instances  of  irregularities  which  are  common  to  individuals 
may  be  noticed  in  the  undue  extension  of  similar  faces  of  crys- 
tals, as  in  quartz,  garnet,  beryl,  &c.  Irregularities  of  this 
kind  do  not  affect  the  inclination  of  those  faces  on  the  primary 
planes,  a  fact  which  is  quite  remarkable.  Faces  are  some- 
times curved,  as  those  of  the  Diamond,  Fluor,  Pearl-spar,  &c. 

Another  instance  of  irregularity  occurs  where  only  a  part  of 
the  crystal  appears,  the  other  part  being  implanted  in  the  sup- 
porting mineral,  a  situation  in  which  most  crystaline  bodies 


M 

d 

20  INTRODUCTION. 

are  formed.  These  individuals  may  however  be  considered  as 
perfect,  since  we  may  complete  the  planes  at  the  defective  ex- 
tremity according  to  the  law  of  symmetry. 

§  52.  Structure  and  Cleavage. 

Crystals  generally  possess  a  regular  structure  which 
may  be  demonstrated  by  cleavage.  By  the  latter  term  is 
meant  the  separation  of  lamina  in  certain  directions. 

If  we  apply  a  knife  to  the  solid  angle  of  a  cube  of  fluor,  in 
a  direction  to  produce  a  tangent  plane,  we  shall  find  that  it 
will  yield,  and  a  portion  of  the  corner  will  be  removed  and  a 
surface  more  or  less  bright  will  appear.  This  plane  will  be 
parallel  to  the  primary  plane  of  the  regular  octahedron.  Again, 
if  we  apply  a  knife  to  the  face  of  a  cubic  crystal  of  common 
salt,  in  a  direction  parallel  to  a  plane,  it  will  yield  readily  and 
present  a  smooth  and  even  surface  parallel  to  the  faces  of  the 
cube.  Instances  of  regular  structure  which  may  be  developed 
by  cleavage  are  numerous,  as  sulphate  of  lime,  rhomb-spar, 
strontia,  barytes,  galena,  mica,  Sfc. 

§  53.  Direction  of  Cleavage. 

The  direction  in  which  a  crystal  can  be  split  is  called 
the  direction  of  cleavage. 

The  direction  of  cleavage  may  depend  upon  the  compara- 
tive force  of  molecular  attraction  in  different  directions,  and 
may  be  so  proportioned  as  to  admit  of  cleavage  in  other  direc- 
tions than  parallel  to  the  primary  planes.  In  instances  of  this 
kind,  the  crystal  is  said  to  possess  two  sets  of  cleavage ;  that 
which  is  parallel  to  the  primary  planes,  is  called  the  primary 
set,  and  that  which  is  not  parallel  to  the  primary  planes,  the 
supernumerary  set. 

§  54.  Cleavage  of  similar  Planes. 

In  primary  forms  whose  faces  are  similar,  the  primary 
cleavages  are  usually  effected,  with  equal  facility,  in  the 
direction  of  those  planes ;  and  the  new  planes  developed 
by  cleavage  will  be  similar  in  lustre  and  general  charac- 
ter. Galena  and  carbonate  of  lime  are  instances. 

When  the  planes  are  dissimilar,  the  primary  cleavage  is  not 
effected  with  equal  facility,  neither  are  the  cleavage  planes 
similar.  Feldspar,  Kyanite,  Sulphate  of  Lime,  are  instances. 
This  enables  us  sometimes  to  determine  what  is  a  primary 
plane. 


INTRODUCTION.  21 

The  terms  single,  double  and  triple,  fourfold  or  sixfold 
cleavage,  have  reference  to  the  primary  form,  and  are  used  to 
express  the  number  of  directions  in  which  a  crystal  can  be 
cleaved.  It  is  plain  that  a  single  solid  only  can  be  obtained 
from  a  triple  cleavage  ;*  but  from  a  four-fold  or  six-fold  cleav- 
age more  than  a  single  solid  can  result. 

§  55.  Nomenclature  of  Cleavage. 

The  nomenclature  of  cleavage  is  expressed  by  terms 
which  indicate  its  direction  in  relation  to  the  axes  of 
primary  forms. 

Conformably  to  this  proposition,  a  cleavage  is  axotomous 
when  it  is  single,  and  takes  place  in  a  direction  perpendicular 
to  the  axis  of  the  primary  form.  It  is  monotonous  if  it  is  sin- 
gle, and  is  either  parallel,  perpendicular  or  inclined  to  the 
axis.  It  is  peritomous  if  it  takes  place  in  two  directions  paral- 
lel to  the  axis.  This  form  of  cleavage  will  result  in  the  pro- 
duction of  four-sided  prisms.  Again,  cleavage  isparatomous 
if  the  number  of  faces  are  indeterminate,  and  the  direction  is 
neither  parallel  nor  perpendicular  to  the  axis.  This  form  of 
cleavage  produces  tetrahedrons  and  octahedrons,  or  pyramids 
generally. 

§56.  Goniometer. 

The  goniometer  is  an  instrument  which*  is  used  for 
measuring  the  angles  at  which  the  planes  of  crystals 
meet.  There  are  two  kinds,  the  common  and  reflecting 
goniometer.  (For  description  and  manner  of  using,  see 
Note  B.) 

§  57.  Determination  of  Primary  Forms. 
Primary  forms  may  sometimes  be  determined  by  the 
direction  of  cleavage,  the  character  of  cleavage  planes, 
and  by  analogy  ;  and  also,  in  the  absence  of  cleavage,  by 
the  character  of  secondary  planes. 

In  case  a  mineral  possesses  a  cleavage  which  leads  to  a 
regular  form,  that  form,  in  general,  is  to  be  considered  as  the 
primary  form,  especially  if  those  cleavages  are  equally  perfect. 

*  To  cleave  neatly,  some  practice  is  necessary.  The  student  will 
need  a  small  light  hammer,  several  knives,  whose  edges  are  even 
but  not  very  thin,  cutting  pincers,  and  an  anvil  of  iron,  lead  or  block 
of  wood,  on  which  to  rest  the  mineral.  Persevering  trials  in  the  way 
of  cleaving  will  be  worth  more  than  any  directions  which  can  be 
given. 


22  INTRODUCTION. 

Thus  Galena  possesses  a  cleavage  in  three  directions,  equally 
perfect  and  leading  to  the  cube ;  the  cube  is  therefore,  to  be 
considered  as  the  primary  form.  For  farther  remarks  on  this 
subject  see,  Note  C. 

§  58.  Fracture. 

Fracture  is  the  mechanical  separation  of  the  particles 
of  a  mineral,  so  as  to  show  its  irregular  structure ;  and 
the  surfaces  thus  produced  are  called  faces  of  fracture. 

The  faces  of  fracture  preserve  no  constant  direction ;  in  this 
particular  they  differ  from  faces  of  cleavage.  It  is  useful  to 
distinguish  several  kinds  of  fracture.  When  the  face  of  frac- 
ture resembles  the  inside  of  a  shell,  it  is  said  to  have  a  con- 
choidal  fracture.  If  the  face  is  smooth,  it  has  an  even  frac- 
ture. If  the  face  presents  numerous  and  small  irregular  pro- 
jections, it  is  said  to  have  an  uneven  fracture.  When  the  face 
presents  the  appearance  of  a  separation  produced  by  tearing, 
it  is  called  a  hackly  fracture, 

§  59.  Surface. 

There  are  four  kinds  of  surface,  viz  :  1.  Faces  of  crys- 
talization.  2.  Faces  of  cleavage.  3.  Faces  of  fracture. 
4.  Faces  of  composition.  For  account  of  these  surfaces 
see  Note  D.  - 

SECTION  II. 

COMPOUND  MINERALS. 

THE  NATURAL-HISTORICAL   PROPERTIES    OF    COMPOUND 
MINERALS. 

§  60.  Regular  Composition. 

The  composition  of -two  or  more  bodies  is  regular  if 
the  form  produced  by  their  connexion  is  regular,  and  join- 
ed in  one  crystaline  form.  -Such  a  composition  is  de- 
signated by  the  name  of  twin  crystal,  or  sometimes  by 
the  term  hemitrope  crystal. 

The  property  peculiar  to  twin  crystals  consists  in  the  close 
and  exact  connexion  of  the  face  of  composition  with  the  series 
of  crystalization  of  the  species.  To  obtain  a  conception  of 
the  situation  of  the  individuals,  we  first  suppose  them  to  be 
in  parallel  position,  and  then  one  of  them  to  turn  round  a  cer- 
tain line,  in  a  determined  direction,  under  an  angle  of  180°, 
while  the  other  remains  unmoved.  This  line  is  the  axis  of 
r  evolution }  and  is  either  perpendicular  to  the  face  of  compo- 


INTRODUCTION*  23 

sition,  or  it  coincides  with  this  face,  and  which  is  parallel  to 
the  crystalographical  axis  of  the  individual.    The  angle  of 

180°  is  the  angle  of  revolution. 

Fig.  23. 

The  character  commonly  taken  for  twin  crys- 
tals is  the  presence  of  a  re-entering  angle.  Fig. 
28,  represents  a  twin  crystal  of  the  green  car- 
bonate of  copper. 

Another  method  of  explaining  the  mode  of  composition  in 
crystals  of  this  kind,  is  to  imagine  the  crystal  to  be  bisected 
by  a  plane  passing  through  it  in  a  determined  direction,  and 
one  of  the  halves  to  be  turned  through  a  certain  number  of  de- 
grees, or  a  number  equal  to  half  the  circumference,  or  180°. 
Hence  the  term  hemitrope  crystals.  '•'..  ., 

§  61.  Irregular  Composition. 

When  a  number  of  crystals  are  aggregated  together  so  that 
one  becomes  the  support  of  the  others,  while  there  exists  no 
general  support,  the  assemblage  is  termed  a  Groupe  of  crys- 
tals. If  several  crystals  are  fixed  to  a  common  basis,  the  as- 
semblage is  termed  a  Geode  of  crystals. 

§  62.  Imitative  Shapes. 

A  compound  mineral  is  said  to  have  an  imitative  shape 
if  it  bears  some  resemblance  to  the  shape  of  a  natural  or 
artificial  body. 

Imitative  shapes  sometimes  result  from  the  groupes  of  crys- 
tals which  assume  globular  or  spheroidal  forms.  Reniform 
and  botryoidal  shapes  may  be  formed  when  globular  or  sphe- 
roidal masses  are  attached  together.  When  the  individuals 
are  very  small  their  surfaces  are  said  to  be  drusy. 

§  63.  Imitative  Shapes  arising  out  of  the  Geodes  of 

Crystals. 

There  are  three  kinds  of  shapes  which  result  from  geodes  of 
crystals.  1.  Those  in  which  the  individuals  spring  from  or 
are  attached  to  a  common  point  of  support.  2.  Those  in 
which  the  individuals  form  one  in  the  support  of  the  other.  3. 
Those  in  which  the  support  is  cylindrical,  sometimes  a  line, 
and  sometimes  a  tube.  Examples  of  the  first  are  furnished  in 
prismatic  Kouphone-spar,  prismatic  Hal-baryte,  rhombohe- 
dral  Iron-ore.  Fruticose  and  dendritic  shapes  likewise  be- 
long to  this  kind.  In  the  second  division  are  included  the 
dentiform,  filiform  and  capillary  shapes.  These  arise  from 
rows  of  crystals  which  mutually  support  each  other.  Somo- 


24  INTRODUCTION. 

times  the  individuals  are  so  extended  laterally  as  to  produce 
leaves  or  membranes.  The  striae  on  their  surfaces  indicate 
their  composition. 

The  third  division  comprehends  the  stalactitic  and  coral- 
loidal  shapes.  Examples  of  individuals  under  these  shapes 
are  found  in  rhombohedral  Lime-haloide,  rhombohedral  Iron- 
ore  ;  also  in  the  Gibbsite,  Flos-ferri,  &c. 

§  64.  Amorphous  Compositions. 
When  the  mass,  formed  by  the  junction  of  several  indi- 
viduals, presents  no  resemblance  to  any  particular  shape, 
and  is  also  irregular,  it  is  said  to  be  massive. 

Massive  minerals  are  usually  composed  of  individuals  of  the 
same  species  which  are  in  contact  on  all  sides.  When  mas- 
sive minerals  are  subdivided  according  to  the  size  of  the  indi- 
viduals, they  are  called  disseminated. 

§  65.  Accidental  Imitative  Shapes. 
When  a  mineral  is  deposited  in  a  space  which  has 
once  been  occupied  by  another  mineral,  it  assumes  the 
shape  of  the  latter,  and  not  from  any  property  peculiar  to 
it.     Such  shapes  are  considered  as  accidental. 

The  space  in  which  such  minerals  are  lodged  may  be  regu- 
lar or  irregular.  Those  shapes  which  are  regular  must  be  de- 
posited in  regular  spaces,  which  have  been  produced  by  crys- 
talization.  Forms  produced  in  those  spaces  are  termed  pseu- 
do-morphous. 

§  66.  Particles  of  Composition. 

The  individuals  forming  the  masses  of  compound  mine- 
rals are  the  particles  of  composition. 

The  differences  to  be  noticed  among  them  arise  from  their 
shape,  arrangement,  size,  and  the  strength  with  which  they 
are  held  together.  They  are  always  the  result  of  crystaliza- 
tion,  but  are  prevented  from  assuming  regular  forms,  from  the 
limited  space  theyv  occupy.  The  shape  depends  on  their 
length,  breadth  and  thickness.  Those  whose  dimensions  are 
equal  in  every  direction  are  termed  granular.  Where  the  in- 
dividuals are  much  extended  in  length,  they  are  said  to  be 
columnar,  and  they  may  be  either  parallel  or  diverging. 
Where  their  breadth  exceeds  the  thickness,  the  composition  is 
called  lamellar.  The  latter  may  be  likewise  parallel  or  di- 
verging. The  size  of  the  individuals  also  vary.  They  may 
be  large,  and  gradually  diminish  until  the  size  is  no  longer 


INTRODUCTION.  25 

perceptible,  when  the  composition  is  said  to  .be  impalpable. 
Individuals  of  some  species  are  always  strongly  connected ; 
of  others  but  feebly.  The  mineral  is  then  said  to  be  friable. 

§  67.  Structure,  of  Compound  Minerals. 
The  structure  of  compound  minerals  differs  materially 
from  that  of  simple  ones.     If  broken  they  present  only 
what  is  termed  faces  of  fracture. 

Some  of  the  kinds  of  faces  of  fracture  have  been  sufficiently 
explained  (§  58.)  The  following  kinds  are  still  to  be  noticed. 
1.  Splintery  fracture,  which  is  produced  by  the  appearance  of 
thin  scaly  particles  on  the  face  of  fracture,  which  are  attached 
to  the  mass  by  their  thicker  ends.  2.  Slaty  fracture,  which 
resembles  imperfect  faces  of  cleavage.  It  is  common  to  the 
different  kinds  of  slate.  3.  Earthy  fracture  resembles  the 
uneven  fracture,  but  belongs  to  decomposed  minerals. 

SECTION  III. 

CONSIDERATION  OP  THE  PROPERTIES  WHICH  BELONG  BOTH  TO 
SIMPLE  AND  COMPOUND  MINERALS. 

§  68.  Division. 

Those  natural-historical  properties  which  are  common 
to  both  the  simple  and  compound  minerals  may  be  divided 
into  the  optical  properties,  and  into  the  physical  proper- 
ties of  minerals. 

The  optical  properties  are  those  which  depend  upon  light, 
and  which  are  not  observable  except  in  its  presence.  They 
are  lustre,  colour  and  transparency.  The  physical  properties 
are  those  which  belong  to  matter  in  the  mass,  excluding  colour, 
lustre,  transparency,  and  those  which  relate  to  the  regular 
forms  of  bodies.  They  are  as  follows :  Hardness,  specific 
gravity,  state  of  aggregation,  magnetism,  electricity,  taste 
and  odor. 

OP  THE  OPTICAL  PROPERTIES  OP  MINERALS. 

§  69.   Colour ,  Lustre  and  Transparency. 
The  phenomena  observable  in  minerals  with  respect  to 
reflected  and  transmitted  light,  are  comprehended  under 
the  heads  of  Colour,  Lustre  and  Transparency. 

§  70.  Colour  and  Streak. 

It  is  necessary  to  distinguish  between  the  colour  of  the 

3 


26  INTRODUCTION, 

entire  mineral  and  that  of  its  powder.  The  former  is 
properly  the  colour  of  the  mineral,  while  the  latter  has 
been  designated  as  that  of  the  streak. 

§71.  Division  of  Colours. 

Colours  are  divided  into  metallic  and  non-metallic 
colours. 

This  distinction  depends  more  on  the  lustre  connected 
with  the  colour  than  on  the  colours  themselves.  Hence  the 
distinction  is  not,  strictly  speaking,  correct ;  but  is  useful,  as 
it  serves  to  distinguish  what  is  merely  useful  from  that  which 
is  indispensible  in  discriminating  minerals. 

§  72.   Metallic  Colours. 

The  metallic  colours  are  :  1.  Copper-red.  2.  Bronze- 
yellow.  3.  Brass -yellow.  4.  Gold-yellow.  5.  Silver- 
white.  6.  Tin-white.  7.  Lead-gray.  8.  Steel-gray. 
9.  Iron-black. 

As  the  colours  which  are  here  enumerated  are  selected  from 
objects  which  are  well  known,  and  of  which  the  student  can 
scarcely  fail  of  obtaining  a  correct  notion,  it  seems  unnecessa- 
ry to  describe  them  more  particularly. 

§  73.  Non-Metallic  Colours. 

In  the  non-metallic  colours  there  is  a  series  of  colours  under 
each  characteristic  colour,  which  is  expressed  by  a  compound 
term.  They  will  be  considered  in  the  consecutive  order  of 
the  principal  kinds,  which  represent  the  general  series  of 
colours.  (See  Note  L.) 

Colours  vary  in  intensity  though  they  belong  to  the  same 
variety,  Differences  of  this  kind  are  expressed  by  pale,  light^ 
deep,  dark.  And  where  there  are  shades  or  varieties  in  the 
series,  they  are  said  to  incline  and  pass  into  one  another. 

§  74.  Peculiarities  in  the  Occurrence  of  Colours. 

The  peculiarities  which  occur  in  colours  which  are 
worthy  of  notice,  are  the  Play  of  Colours,  Change  of  Col- 
ours, Opalescence,  Iridescence,  Tarnish,  and  Dichroism. 

The  play  of  colours  is  that  property  which  minerals  possess 
of  exhibiting  coloured  points  of  great  intensity,  which  change 
with  the  position  of  the  mineral,  or  with  the  direction  of  the 
rays  of  light.  Examples  are  found  in  the  Diamond  and  Opal. 

Change  of  colour  consists  in  the  reflection  of  bright  hues  of 
colour  in  certain  directions.  The  Labrador  feldspar  is  a  re- 
markable instance. 


INTRODUCTION.  27 

Opalesccnce  consists  in  a  kind  of  milky-white  light,  which 
is  reflected  from  natural  and  artificial  faces.  This  property 
may  be  seen  in  the  Cats-eye  and  Moonstone.  Jn  the  former 
it  depends  on  composition,  and  in  the  latter  on  regular  struc- 
ture. 

Iridescence  is  the  reflection  of  the  coloured  rays  of  light 
similar  to  the  rainbow.  It  is  generally  produced  by  fissures, 
and  depends  on  accidental  circumstances. 

Dichroism  is  a  property  of  showing  different  colours  in  trans- 
mitted light,  in  different  determined  directions.  It  depends  on 
form  and  structure.  Rhombohedral  Tourmaline  and  prismatic 
Quartz  are  among  the  most  distinct  examples.  Of  the  former 
some  varieties  are  opake  when  viewed  in  the  direction  of  the 
axis,  but  in  directions  perpendicular  to  it  they  possess  con- 
siderable transparency,  and  show  the  different  colours,  as 
green,  brown  and  blue. 

The  tarnish  consists  in  the  alteration  of  the  colour  of  a  mine- 
ral on  the  surface.  It  ought  not  to  be  confounded  with  the 
real  colour  of  the  mineral.  Metallic  minerals  are  most  liable' 
to  suffer  this  change. 

§  75.  The  Streak. 

If  a  mineral  is  scratched  with  a  hard  instrument,  either 
a  powder  will  be  produced  or  the  surface  will  assume  a 
higher  degree  of  lustre.  Both  these  effects  are  compre- 
hended under  the  expression,  the  streak. 

The  streak  is  said  to  be  unchanged  when  the  powder  retains 
the  colour  of  the  mineral.  A  white  or  gray  streak  is  said  to 
be  uncoloured. 

§  76.  Degrees  of  Transparency. 
The  degrees  of  transparency  depend  on  the  quantity  of 
light  which  is  transmitted  through  minerals. 
These  degrees  may  be  noticed  as  follows  : 

1.  Transparent,  if  sufficient  light  is  transmitted  to  enable 
us  to  see  small  objects  placed  behind  the  mineral. 

2.  Semi-transparent,  if  it  is  possible  to  distinguish  the  gene- 
ral outline  of  bodies  placed  behind  them. 

3k  Translucent,  when  a  small  quantity  of  light  only  falls 
into  the  mineral,  but  not  sufficient  to  enable  us  to  discover  ob- 
jects behind  them. 

4.  Translucent  on  the  edges,  when  only  the  acute  edges 
transmit  a  feeble  quantity  of  light. 

5.  Opake,  if  the  mineral  transmits  no  light  at  all.    The  mine- 
rals of  the  orders  Metal,  Glance  and  Pyrites  are  usually  opake. 


28  INTRODUCTION. 

$  77.  Lustre. 

The  lustre  of  a  mineral  arises  from  the  reflection  of 
light  from  its  surfaces,  and  is  to  be  considered  as  to  its 
kind  and  to  its  intensity. 

The  kinds  of  lustre  are  metallic,  adamantine,  resinous,  vitre- 
ous and  pearly. 

Metallic  lustre  is  divided  into  perfect  and  imperfect  metallic 
lustre.  The  perfect  occurs  in  all  the  species  of  the  orders 
Metal,  Pyrites  and  Glance,  and  is  the  same  as  occurs  in  brass, 
silver,  copper  and  gold.  The  second  is  found  in  the  ores,  as 
in  prismatic  Scheelium-ore,  octahedral  Copper-ore,  &c. 

Adamantine  lustre  is  divided  into  metallic  adamantine  and 
common  adamantine  lustre.  Examples  of  the  first  are  found 
in  the  order  Blende,  especially  those  species  which  have  a 
dark  colour.  The  common  adamantine  lustre  is  peculiar  to 
octahedral  Diamond,  the  pale  coloured  varieties  of  Ruby- 
blende  and  Garnet-blende,  and  to  some  varieties  of  di-prismat- 
ic  Lead-baryte. 

Resinous  lustre  is  that  which  a  mineral  presents  when  it  re- 
sembles that  of  resin.  It  occurs  in  pyramidal  Garnet,  and  in 
the  varieties  of  empyrodox  Quartz,  or  Pitchstone. 

Vitreous  lustre  is  that  of  common  glass,  and  may  be  ob- 
served in  common  Quartz. 

Pearly  lustre  is  divided  into  common  and  metallic  pearly* 
Examples  of  the  first  may  be  observed  in  prismatic  Disthene- 
spar,  and  in  some  species  of  the  order  Mica  ;  the  second  in 
the  species  of  Schiller-spar. 

The  following  are  the  degrees  of  lustre.  1.  Splendent.  2. 
Shining.  3.  Glistening.  4.  Glimmering.  5.  Dull. 

Splendent  surfaces  possess  the  highest  degree  of  lustre  and 
resemble  polished  steel. 

Shining  is  a  less  degree  but  is  still  lively,  but  not  suffi- 
ciently strong  to  exhibit  the  distinct  image  of  an  object  from 
its  surface. 

Glistening  surfaces  reflect  light  disorderly  and  rather  in  de- 
fined patches.  Common  to  many  compound  minerals  when 
the  particles  of  composition  are  discernable. 

Glimmering  does  not  reflect  light  in  defined  patches,  but  a 
mass  of  defined  light  seems  spread  over  the  glimmering  sur- 
face. This  degree  belongs  to  compound  minerals,  whose  par- 
ticles of  composition  are  very  small. 

Dull  possesses  no  lustre  at  all,  and  is  mostly  confined  to 
decomposed  minerals. 

In  general  the  kind  and  degree  of  lustre  which  crystahzec 
Bodies  present  are  pretty  uniform.  The  gradation  which  may 


INTRODUCTION.  29 

sometimes  be  observed  presents  a  continuous  series,  which 
allows  of  the  same  application  as  the  series  in  the  varieties 
of  colours.  In  crystals  similar  faces  agree  as  to  the  kind  and 
intensity  of  lustre,  and  vice  versa,  such  faces  which  do  not 
agree  in  lustre  are  not  similar.  (For  an  account  of  Double 
Refraction  and  Polarization  of  Light,  see  Note  E.) 

OP  THE  PHYSICAL  PROPERTIES  OF  MINERALS. 

§  78.  Explanation. 

The  properties  of  minerals  which  are  termed  physical, 
comprehend  all  those  which  neither  depend  upon  form, 
nor  upon  the  presence  or  absence  of  light. 

Among  these  are  the  State  of  Aggregation*  Hardness, 
Specific  Gravity i  Magnetism,  Electricity,  Taste  and  Odour. 

§  79.  State  of  Aggregation. 

Minerals,  in  regard  to  their  state  of  aggregation,  are 
distinguished  into  solid  and  fluid  minerals. 

A  solid  mineral  may  be  brittle,  malleable,  sectile,  ductile, 
flexible  and  elastic. 

A  fluid  mineral  may  be  liquid,  viscid  and  expansible.  All 
these  properties  may  pass  into  each  other  by  insensible  grada- 
tions. 

§  80.  Hardness. 

Hardness  is  the  resistance  which  solid  minerals  offer 
to  the  displacement  of  their  particles.  The  magnitude  of 
this  resistance  is  termed  their  degree  of  hardness. 

Hardness  is  one  of  the  most  useful  properties  in  the  natural 
history  of  the  mineral  kingdom,  particularly  in  the  determina- 
tive part.  The  existence  of  different  degrees  of  hardness  is 
easily  ascertained ;  but  to  form  an  accurate  scale  of  hardness 
is  very  difficult.  A  scale  of  hardness  which  shall  answer  the 
purposes  of  mineralogy  may  be  formed  by  choosing  a  certain 
number  of  minerals,  of  which  every  preceding  one«is  scratched 
by  the  one  which  follows  it,  taking  care  that  the  intervals  be- ' 
tween  every  two  members  of  the  scale  be  not  so  disproportion- 
ate as  to  render  its  employment  uncertain  or  difficult.  The 
following  minerals  have  been  selected  to  represent  the  degrees 
of  hardness,  and  the  numbers  which  are  affixed  to  them  express 
respectively  their  comparative  degrees  of  hardness.  1.  Pris- 
matic talc-mica.  2.  Prismatoidal  gypsum-haloide,  which  is 
the  same  as  hexahedral  rock-salt.  3.  Rhombohedral  lime- 
hakide.  4.  Octahedral  Jluor-haloide,  5.  Rhombohedral fluor* 
3* 


SO  INTRODUCTION. 

haloide.  6.  Prismatic  feldspar.  7.  Rhombohedral  quartz. 
8.  Prismatic  topaz.  9.  Rhombohedral  corundum.  10.  Oc- 
tahedral diamond. 

This  scale  is  employed  by  endeavoring  to  find  the  place 
which  a  mineral  occupies  in  it,  by  scratching  the  different 
numbers,  and  the  degree  is  expressed  by  saying  that  the  mine- 
ral equals  a  particular  number.  Thus,  in  speaking  of  the 
hardness  of  hexahedral  rock  salt,  it  is  said  that  its  hard- 
ness =2  or  is  2. 

§81.  Specific  Gravity. 

If  we  suppose  the  absolute  weight  of  one  of  two  bodies 
which  possess  the  same  volume  to  be  =1,  the  ratio  of  the 
absolute  weight  of  the  other  to  this  unit  is  termed  its 
specific  gravity. 

As  we  cannot  secure  sufficient  accuracy  merely  by  sight  or 
by  estimate,  it  is  necessary  that  we  use  appropriate  instru- 
ments to  ascertain  the  specific  gravities  of  bodies.  (For  the 
description  and  use  of  an  instrument  of  this  kind,  see  Note  F.) 

§  82.  Magnetism. 

Some  minerals,  on  being  brought  within  a  certain  distance 
of  a  magnetic  needle,  act  upon  it.  Others  become  magnets 
themselves.  Both  of  these  phenomena  are  used  as  charac- 
ters under  the  name  of  magnetism.  (See  Note  G.) 

§83.  Electricity. 

The  different  relations  which  different  bodies  sustain  to 
the  electric  fluid,  may  be  usefully  applied  as  characters  of 
minerals. 

Some  minerals  become  electric  by  friction,  some  by  pres- 
sure, and  others  by  heat.  Vitreous  electricity  is  produced  by 
friction  in  most  minerals  which  belong  to  the  orders  Spar, 
Gem,  Mica  and  Baryte.  And  resinous  electricity  is  produced 
in  the  same  way  in  the  orders  Sulphur,  Resin  and  Coal.  The 
conductors  of  electricity  belong  mostly  to  the  orders  Metal, 
Pyrites  and  Glance. 

§  84.  Taste. 

Several  minerals,  solid  as  well  as  fluid,  produce  a  sensible 
taste.  The  different  kinds  of  taste  are,  1.  Astringent.  2. 
Sweetish.  3.  Saline.  4.  Alkaline.  5.  Cooling.  6.  Bit- 
ter. 7.  Urinous.  8.  Sour. 

§85.   Odor. 

Some  minerals  when  rubbed  or  warm,  emit  some  odor 
which  may  afford  useful  characters. 


INTRODUCTION.  31 

The  black  mineral  resins  possess  a  bituminous  odor ;  the 
species  of  the  genus  Iron-pyrites  emit  a  sulphureous  odor,  and 
the  arsenical  Iron-pyrites  emits  the  odor  of  garlic.  Other 
kinds  might  be  mentioned,  but  it  is  unnecessary, 

§  86.  Chemical  Characters. 

Chemical  characters  are  those  which  are  observed  in  bod- 
ies after  some  essential  change  has  been  wrought  upon  them. 

The  chemical  characters  which  are  made  use  of  are  confined 
to  the  use  of  the  blow-pipe  and  the  action  of  acids.  These 
characters  have  no  place  in  a  treatise  of  this  kind,  as  they  do 
not  belong  to  the  natural-historical  properties.  But  that  the 
student  may  be  furnished  with  every  aid  in  the  investigation 
of  minerals,  a  particular  account  of  these  characters  is  given 
in  Note  H. 

PART  II. 

THEORY  OP  THE  SYSTEM. 

§  87.  Identity. 

Natural  productions  which  do  not  differ  in  their  natu- 
ral-historical properties  are  identical. 

The  consideration  of  this  proposition  supposes  a  separation 
of  all  accidental  differences  in  two  bodies ;  such  as  the  size  of 
two  individuals  and  the  disproportional  enlargement  of  their 
faces,  and  their  junction  with  other  individuals.  By  con- 
sidering two  bodies  as  identical,  is  meant  that  every  one  of 
them  may  be  substituted  in  the  place  of  the  other  in  every 
natural-historical  respect.  So  that  if  one  belongs  to  a  par- 
ticular  species  the  other  must  necessarily  belong  to  it. 

§88.   Difference. 

Individuals  which  do  not  agree  in  their  natural-histor- 
ical properties  are  not  identical. 

If  two  individuals  differ  as  to  crystaline  form,  hardness  or 
specific  gravity,  or  in  only  one  of  these  properties,  they  will 
not  be  identical.  The  same  degree  of  difference,  cannot  be 
said  to  exist  between  every  two  individuals.  Thus  there  is 
less  difference  between  epidote  and  ziosite  than  between 
epidote  and  quartz.  There  is  a  less  difference  between  two 
crystals  of  garnet,  one  of  which  is  a  rhombic  dodecahedron, 
and  the  other  a  trapezoedron— -than  between  either  of  them  and 
a  crystal  of  gold :  which  is  sufficient  to  show  that  the  degrees 
of  difference  are  not  the  same  in  every  two  individuals. 

§  89.   Species. 
An  assemblage  of  individuals  which  are  brought  under 


32  INTRODUCTION: 

the  idea  of  identity  constitutes  a  species :  and  the  individu- 
als belonging  to  it  are  homogeneous  individuals. 

Under  this  definition,  the  idea  of  a  species  becomes  the 
foundation  of  scientific  mineralogy,  and  is  the  starting  point 
from  which  to  obtain  some  knowledge  of  all  the  productions  of 
the  mineral  kingdom,  when  we  wish  to  preserve  a  certain  unity 
in  the  acquirement  of  our  information. 

Individuals  which  constitute  a  species  often  possess  a  series 
of  characters  by  which  they  pass  or  graduate  into  each  other ; 
but  individuals  belonging  to  two  species  never  pass  into  each 
other,  as  individuals  connected  by  transitions  are  homogene- 
ous, and  belong  to  one  and  the  same  species. 

The  continuity  which  exists  in  the  series  of  the  characters 
of  individuals  is  such,  that  all  their  differences  may  be  joined 
into  a  whole.  This  enables  us  to  comprehend  all  the  varieties 
under  one  species,  and  also  in  the  mineral  kingdom  ;  so  that 
it  is  not  for  the  interest  of  mineralogy  that  the  species  should 
be  subdivided,  or  distinguished  into  sub-species  and  varieties. 
The  species  itself  is  the  proper  object  of  classification,  or  the 
thing  to  be  classed.  The  idea  of  the  species  is  not  produced 
by  classification. 

§  90.  Genus. 

An  assemblage  of  species  connected  by  the  highest  de- 
gree of  resemblance  is  termed  a  genus. 

The  resemblance  which  shall  constitute  a  genus  is  not  arbi- 
trarily fixed,  and  it  is  impossible  to  express  it  in  one  or  in  a 
certain  number  of  characters.  A  resemblance  is,  however, 
manifest  by  occular  inspection.  Striking  examples  are  fur- 
nished in  the  genera  Garnet,  Iron-pyrites,  Kouphone-spar, 
ffal-baryte,  Lead-baryte,  #c. 

§91.   Order. 

The  order  is~an  assemblage  of  similar  genera. 

The  orders  in  the  mineral  kingdom  are  the  same  as  the  natu- 
ral families  of  the  vegetable  kingdom,  and  their  reception  and 
determination  in  one  and  the  other,  depend  upon  the  same 
principles.  Where  can  be  found  in  the  vegetable  kingdom 
families  more  natural  than  are  the  group  of  genera  in  the  or- 
ders Spar,  Ore  and  Pyrites?  Where  the  principles  of  natural 
history  are  applied  in  conformity  to  its  proper  objects,  the  re- 
sult will  always  be  happy,  and  the  employment  of  characters 
jnder  the  guidance  of  those  principles  can  never  fail  of  devel- 
oping the  system  intended.  Thus,  a  chemical  system  of  mine- 
ralogy would  require  for  its  developement  principles  and  char- 


INTRODUCTION.  33 

acters  peculiar  to  that  science.     When  a  mixed  method  is  fol- 
lowed, confusion  and  obscurity  must  be  the  prominent  features, 

§92.   Class. 
The  class  is  an  assemblage  of  similar  orders. 

The  inspection  of  the  three  classes  in  mineralogy  will  prove 
the  orders  in  each  class  to  resemble  each  other  in. their  natu- 
ral-historical properties,  more  closely  than  those  in  the  other 
classes.  For  instance,  the  order  Spar  has  a  greater  resem- 
blance to  the  order  Gem,  than  to  the  order  Coal  or  Resin,  prov- 
ing that  the  idea  of  class  depends  also  upon  natural-historical 
relations,  and  does  not  admit  of  foreign  principles,  and  is  not 
produced  by  mere  division. 

PART  III. 

NOMENCLATURE. 

§  93.   Definition, 

The  systematic  nomenclature  is  the  assemblage  of  those 
denominations  which  natural  history  applies  to  natural 
productions^  and  which  refer  to  a  natural-historical  sys- 
tem. 

The  systematic  nomenclature  provides  every  natural  pro- 
duction with  a  denomination,  and  represents  by  these  denomi- 
nations the  natural-historical  resemblance  by  which  these 
bodies  are  connected  in  the  system.  The  species  is  the  foun- 
dation, and  the  systematic  nomenclature  the  verbal  expression 
of  the  system.  The  species  therefore  is  the  object  to.  which 
the  systematic  denomination  refers. 

§94.   Object  of  the  Names. 

The  ideas  expressed  by  the  names  are  the  higher  uni- 
ties of  classification,  immediately  preceding  that  of  the 
species. 

The  name  is  to  be  applied  to  an  assemblage  of  natural  pro- 
ductions, and  belongs  to  a  single  species  or  individuals,  only 
so  far  as  the  one  or  other  belongs  to  the  assemblage  in  virtue 
of  their  natural  historical  properties.  This  points  out  the  dif- 
ference between  the  systematic  nomenclature  and  the  trivial 
nomenclature.  The  latter  applies  the  name  directly  to  the 
object,  without  expressing  the  connexion  of  bodies.  The 
trivial  nomenclature  is  wholly  arbitrary  in  the  selection  of  its 
names. 


34  INTRODUCTION. 

§  95.  Name  of  the  Order. 

In  the  natural  history  of  the  mineral  kingdom,  the  order  is  the  highest  idea 
expressed  in  the  systematic  nomenclature.  The  order  consequently  will  bear 
the  simple  name. 

<§>  96.  Selection  and  Signification  of  the  Names  of  the 

Orders. 

The  simple  names  are  the  foundation  of  the  whole  no- 
menclature, and  receive  their  signification  in  agreement 
with  the  ideas  of  the  orders. 

The  names  are  Gas,  Water,  Acid,  Salt,  Haloide,  Baryte,  Kerate,  Mala- 
chite, <Spar,  Gem,  Ore,  Metal,  Pyrites,  Glance,  Blend,  Sulphur,  Resin  and 
Coal. 

§  97.  Name  of  the  Genus. 

In  the  genus  the  name  of  the  order  is  restricted  by  con- 
necting another  word  with  the  name  of  the  order  ;  and  thus 
a  compound  word  is  formed,  which  is  the  generic  name. 

The  generic  name  refers  to  the  natural-historical  properties  of  the  genus. 
It  is  therefore  intended  to  express  by  il  some  striking  feature  of  its  resemblance 
with  other  bodies.  Thus  the  name  Garnet-blende  indicates  that  it  belongs  to 
the  order  Blende,  and  that  the  individuals  it  contains  have  a  Garnet-like  ap- 
pearance. ' 

§  98.  Denomination  of  the  Species. 
The  denomination  of  the  species  is  effected  by  the  use 
of  an  adjective. 

The  adjective  which  is  employed  for  this  purpose  is  selected  from  the  na- 
tural-historical properties,  and  if  possible  is  one  which  is  the  most  useful  in  dis- 


tinguishing it  from  other  species.  The  most  desira'ble  are  those  which  relate 
to  form  and  cleavage.  Examples  are  hexahedral,  prismatic,  rhombohedral  Iron- 
pyrites  ;  orperitomous  and  pyramidal  rhombohedral  Titanium-ore;  prismatic 


to  form  and  cleavage.  Examples  are  hex&hedral,  prismatic,  rhombohedral  Iron- 
pyrites  ;  orperitomous  and  pyramidal  rhombohedral  Titanium-ore;  prismatic 
rhombohedral,  macrotyphus,  paratomous  Lime-haloide.  In  this  way  the  stu- 


dent is  furnished  in  the  denomination  of  the  species  with  an  image  or  represen- 
tation of  it,  which  indeed  will  not  answer  in  the  place  of  the  characteristic  or 
general  description. 

§  99.  Trivial  Nomenclature. 

In  the  trivial  nomenclature  the  name  is  fixed  upon  the 
species. 

The  trivial  nomenclature  does  not  express  the  connexion  among  bodies 
which  it  provides  with  names.  Any  name  which  does  not  eipress  this  con- 
nexion is  a  trivial  name,  which  rests  upon  the  lowest  idea  of  the  system,  that 
ia,  upon  the  species. 

The  natural-historical  determination  of  natural  productions,  does  not  go  be- 
3'ond  the  species.  The  systematic  nomenclature  stops  therefore  at  the  de- 
jnomination ;  the  trivial  nomenclature  at  the  name  of  the  species. 

PART  IV. 

CHARACTERISTIC. 

$  100.  Definition. 
The  characteristic  is  an  assemblage  of  certain  natural- 


INTRODUCTION.  35 

historical  properties,  arranged  according  to  a  certain  sys- 
tem, for  the  purpose  of  distinguishing  the  unities  contain- 
ed in  the  system. 

A  single  property  or  collection  of  these,  if  subservient  to  the  distinction  of  the 
several  species  of  a  genus,  or  of  the  genera  of  an  order,  or  the  orders  of  a  class, 
&c.  is  termed  a  character,  and  the  single  properties  it  contains,  character- 
istic marks  or  terms.  According  to  this  definition,  the  existence  of  a  character 
presupposes  the  existence  of  a  system  to  which  it  applies. 

§  101.   Properties  of  the  Characters. 

The  characters  must  be  sufficient  to  a  precise  distinction  within  their  respec- 
tive spheres,  and  as  short  as  the  necessary  degree  of  evidence  in  the  determi- 
nation of  the  species  will  allow.  It  may  be  remarked  that  characters  are  en- 
tirely useless,  if  they  are  ambiguous  or  apply  equally  well  to  two  distinct  natur- 
al productions.  The  characters  require  both  conciseness  and  uniformity  : 
hence  the  character  should  not  contain  any  thing,  but  what  is  required  for  the 
distinction  and  the  evidence  of  the  determination  of  the  species. 

§  102.  Absolute  and  Conditioned  Characteristic  Maries. 
A  characteristic  mark  is  absolute  if  it  is  by  itself  distinctive 
in  its  sphere ;  a  conditioned  mark  is  only  distinctive  under 
certain  circumstances  or  restrictions. 

In  illustration  of  the  proposition,  if  a  solid  mineral  shall  belong  to  the  first 
class,  it  must  be  sapid,  the  character  of  this  class  is  therefore  solid:  taste, 
where  solidity  is  the  condition  under  which  the  property  of  exciting  taste  must 
necessarily  take  place.  If  the  mineral  is  not  solid  it  is  no  matter  whether  it 
has  taste  or  not ;  hence  the  marks  or  characters  must  be  taken  literally,  and 
they  admit  of  no  other  signification  than  that  expressed  by  the  words. 

>:      §  103.  Base  of  a  Perfect  Characteristic. 
The  perfection  of  the  characteristic  depends  upon  the 
perfection  and  accuracy  of  our  natural-historical  knowledge 
of  natural  productions. 

Our  ideas  of  a  system  of  nature  will  advance  towards  perfection,  the  more 
we  inquire  into  the  nafure  of  bodies,  and  study  their  relation  towards  each  oth- 
er, and  as  our  knowledge  increases  the  more  correct  will  be  our  views,  and  the 
nearer  to  perfection  shall  we  be  able  to  construct  a  characteristic. 

$  104.   Use  of  the  Characteristic. 
The  use  of  the  characteristic  is  to  determine  the  name 
of  a  natural  production. 

(For  process  in  determining  minerals,  &c.,  see  Note  K.) 

PART  V. 

PHYSIOGRAPHY. 

§  105.  Definition. 
Physiography  means  a  description  of  natural  productions 

Physiography  is  not  fitted  to  the  purpose  of  distinguishing  minerals  or  other 
natural  productions,  We  cannot  by  its  assistance  find  the  place  of  a  given  min- 


36  INTRODUCTION. 

•eralin  the  system,  or  in  other  words  recognise  it,  for  it  is  independent  of  that 
natural  connexion  among'  bodies  upon  which  systems  are  founded.  A.  descrip- 
tion is  not  a  character,  since  the  peculiarity  of  a  character  consists  in  its  being 
composed  of  a  smaller  number  of  characteristic  terms  than  may  be  observed  in 
the  objects  characterised. 

The  description  presupposes  nothing  but  Terminology.  It  is  perfectly  in- 
different what  nomenclature  is  made'use  of,  provided  the  names  serve  to  keep 
separate  the  objects  which  really  differ  from  each  other. 

§  106.   Objects  of  Physiography. 
The  object  which  physiography  serves  in  the  mineral 
kingdom,  is  the  description  of  the  individual. 

Individuals  are  described  by  indicating  all  the  natural  historical  properties. 
In  enumerating  these  a  certain  order  should  be  fixed  upon  for  the  sake  of  per- 
spicuity, which  should  not  be  altered.  All  prolixity  should  likewise  be  avoided, 
and  every  thing  foreign  to  the  purpose  rejected. 

§  107.   General  Description  of  the  Species. 

In  order  to  represent  the  natui-al-historical  species  in  the  mineral  kingdom, 
it  is  necessary  to  coni-truct  a  general  description  which  shall  give  a  correct  idea 
of  all,  or  at  least  all  known  varieties  of  a  species  in  their  proper  connexion. 
The  method  of  constructing  a  general  description  is  as  follows.  First,  any 
suitable  variety  of  the  species  is  chosen  and  described  with  all  possible  accura- 
cy. The  description  will  contain  only  single  characters,  consisting  of  a  cer- 
tain colour  and  lustre  ;  a  certain  degree  of  hardness;  a  certain  form,  &c.  all  of 
which  are  members  of  their  respective  series.  If  in  the  place  of  .every  one  of 
these  single  characters,  we  substitute  the  complete  series  to  which  it  belongs, 
the  description  of  the  individual,  or  of  the  variety,  is  transformed  into  the  col- 
lective or  general  description  of  the  species. 

§  108.  Arrangement  of  the  General  Descriptions. 
The  general  or  collective  descriptions  require  to  be  so 
arranged,  as  to  facilitate  their  use,  and  to  produce  a  com- 
plete view  of  the  species. 

The  characters  which  depend  on  the  presence  of  light  serve  very  much  to 
create  and  enliven  the  image  of  the  species,  such  as  the  colour,  lustre  and  trans- 
parency, all  of  which  .should  be  particularly  noticed  next  to  (he  form  arid  cleav- 
age, together  with  the  character  of  the  different  faces,  and  will  contribute  to  fill 
up  in  our  minds,  a  notion  of  the  individuals  described^  These  are  to  be  follow- 
ed by  the  hardness  and  specific  gravity,  after  which  the  compound  forms,  their 
composition,  &c.  will  serve  to  complete  a  perfect  representation  of  the  spe- 
cies. 

§  109.  The  Collective  Descriptions  do  not  depend  on  the, 
Systems. 

The  natural-historical  species  itself  is  the  basis  of  every  method,  and  in  fact 
of  every  science  ;  it  is  the  object,  not  the  product  of  classification.  The  de- 
scriptions are  applicable  therefore  in  every  system,  even  though  the  principles 
upon  which  it  is  framed  should  not  agree  with  those  of  Natural  History.  Thus 
the  collective  description  is  raised  to  a  high  degree  of  importance,  since  it  be- 
comes the  link  between  Natural  History  and  other  sciences,  referring  likewise 
to  the  Mineral  Kingdom.  When  the  collective  descriptions  are  completed, 
Natural  History  has  fulfilled  its  duty,  and  the  species  is  now  prepared  to  be 
the  subject  of  farther  investigation  in  other  sciences.  The  classifiable  unity 
itself  may  be  clearly  designated  and  distinguished  from  every  other  object. 


MANUAL 

OF 

MINERALOGY  AND  GEOLOGY. 


CLASS  I. 

ORDER  I.     GAS. 
GENUS  I.    MARSH  GAS. 

I.  EMPYREUMATIC  HYDROGEN  GAS. 

Carburelted  Hydrogen  Gas.     Jam. 

Amorphous.  Transparent  and  expansible.  Odor  slight- 
ly empyreumatic.  Sp.  gr.  0.570.  Berzelius. 

1.  The  colour  of  litmus  paper  when  exposed  to  the  influence 
of  this  gas,  is  unchanged.     Jt  is  highly  inflammable,  and  burns 
with  a  yellow  flame.     It  detonates  powerfully  when  mixed  with 
atmospheric  air,  and  fired  with  the  electric  spark.     Jt  is  com- 
posed by  weight  of 

Carbon      6,  or  one  p. 
Hydrogen  2,        two  p. 

2.  Carburetted  hydrogen  is  formed  abundantly  in  stagnant 
pools,  from  which  it  escapes  in  bubbles  when  the  mud  at  the 
bottom  is  stirred  or  agitated. 

It  is  likewise  developed  in  coal  mines,  and  is  identical  with 
that  dangerous  compound  known  among  miners  as  the  fire- 
damp. Accidents  arising  from  the  explosion  of  this  gas  are 
much  less  frequent  since  the  invention  of  the  safety  lamp  by 
Sir  Humphrey  Davy. 

2.  SULPHURETTED  HYDROGEN  GAS.    Jam. 
Colourless   and    transparent.      Odor   of  putrid  eggs. 
Taste  offensive.     Sp.gr.  1.18.     Berzelius. 

1.  Sulphuretted  hydrogen  is  not  a  supporter  of  combustion, 
as  a  flame  is  extinguished  when  immersed  in  it.  When  in. 


38  ATMOSPHERIC   GAS. 

| 

flamed,  it  burns  with  a  pale  blue  light.  It  is  found  to  possess 
acid  properties,  for  it  reddens  litmus  paper,  and  forms  salts 
with  alkalies ;  hence  it  is  sometimes  called  hydro-sulphuric 
acid. 

From  its  affinity  for  the  metallic  oxides,  it  is  a  chemical  agent 
of  great  importance.  It  tarnishes  gold  and  silver,  forming  with 
them  sulphurets.  It  instantly  blackens  the  carbonate  of  lead ; 
for  this  reason  it  is  often  used  as  a  test  of  its  presence.  It 
consists  of 

Sulphur   16,  one  p. 

Hydrogen  1,  one  p. 

2.  This  substance  is  a  poison  of  considerable  energy,  as  it 
is  fatal  to  small  animals,  if  it  constitutes  only  a  small  propor- 
tion of  the  air  which  they  inhale. 

3.  Sulphuretted  hydrogen  is  mostly  found  in  connexion  with 
those  rocks  which  abound  in  pyrites  and  coal ;  thus  it  is  found 
issuing  from  the  western  bank  of  Niagara  river,  a  mile  south 
of  the  Falls :  the  rock  is  the  shelly  limestone,  which  contains 
thin  seams  of  coal  and  iron  pyrities.     It  occurs  also  under  the 
same  circumstances  near  the  Otsquaga  creek.     Eaton. 

GENUS  II.    ATMOSPHERIC  GAS.    j 

1.  PURE  ATMOSPHERIC  GAS. 

Pure  Atmospheric  Mr.    Jam. 

Colourless  and  transparent.  Without  odor  or  taste.  Sp. 
gr.  1.00. 

1.  Pure  atmospheric  air  consists  of  SO  nitrogen,  20  oxy- 
gen, and  0.001  carbonic  acid. 

Or  of  Nitrogen  4  p. 
Oxygen    1  p. 

The  proportions  of  oxygen  and  nitrogen  are  constant ;  but  that 
of  carbonic  acid  is  variable.  This  compound  constitutes  the  at- 
mosphere, and  surrounds  the  whole  globe. 

2.  Atmospheric  air  is  compressible  and  elastic.     One  hun- 
dred cubic  inches  at  the  temperature  of  60°  of  F.  and  when 
the  mercury  of  the  barometer    stands  at  30  inches,  weigh 
30.5  grs.     It  is  828  times  lighter  than  pure  water,  and  near 
11260  times  lighter  than  mercury.     The  height  of  the  atmos- 
phere above  the  level  of  the  sea  is  supposed  to  be  about  45 
miles,  and  its  pressure  on  every  square  inch  of  surface,  is  equal 
to  151bs.  hence  it  is  capable  of  supporting  a  column  of  mercury 
30  inches  high,  and  one  of  water  of  34  feet.    It  is  well  known 


WATER — CARBONIC   ACID.  39 

that  as  we  recede  from  the  surface  of  the  earth  and  ascend  into 
the  higher  regions,  the  pressure  decreases ;  this  may  be  shown 
by  the  barometer,  and  by  boiling  water  on  elevated  situations. 

2.  NITROGEN  GAS. 

Colourless  and  transparent.     Without  odor  or    taste. 
'  Expansible.  Not  a  supporter  of  combustion  or  combustible. 
Sp.  gr.  0.972. 

1.  One  hundred  cubic  inches  at  the  mean  temperature  and 
pressure,  weigh  29.65  grs.  Turner. 

It  issues  from  many  springs  in  the  valley  of  the  Hoosic,  and 
in  some  of  them,  in  considerable  quantities.  It  contains  usual- 
ly oxygen  in  mixture,  not,  perhaps,  varying  much  from  10  per 
cent. 

ORDER  II.    WATER. 
-  GENUS  I.    METEORIC  WATER. 

1.  PURE  METEORIC  WATER. 

Colourless  and  transparent.  Without  odor  or  taste. 
Amorphous.  Liquid.  Sp.  gr.  1.00. 

Water  when  heated  to  212°  F.  passes  into  the  form  of  va- 
por, and  when  it  cools  to  32°  F.  congeals,  or  becomes  solid. 
It  is  composed  of 

Oxygen      S&94. 

Hydrogen  11.06.     Berzelius. 

As  found  in  springs  and  fountains  it  usually  contains  an  admix- 
ture of  the  alkaline  and  earthy  salts,  as  lime,  magnesia  and  soda. 
These  impurities  are  removed  by  distillation.  Water  when 
crystallized  usually  assumes  the  form  of  a  star,  with  six  radii. 
The  primary  form  appears  to  be  a  prism,  but  its  dimensions 
have  not  yet  been  satisfactorily  determined. 

ORDER  III.     ACID. 
GENUS  I.    CARBONIC  ACID. 

1.  AERIFORM  CARBONIC  ACID. 

Colourless  and  transparent.  Taste  slightly  acid.  Odor 
pungent.  Amorphous.  Sp.  gr.  1.51.  Biot  and  Arago. 


40  SULPHURIC    ACID. 

1.  Carbonic  acid  reddens  the  vegetable  blues,  and  forms  a 
turbid  compound  when  agitated  with  lime  water.     It  extinguish  - 
es  all  burning  bodies,  and  destroys  life  if  inhaled  into    the 
lungs,  by  its  poisonous  qualities,  as  well  as  by  excluding  oxy- 
gen.    When  absorbed  by  water  it  communicates  an  acidulous 
taste.     It  consists  of 

Carbon    6,  one  p. 
Oxygen  16,  two  p. 

2.  Carbonic  acid  is  always  present  in  the  atmosphere  ;  even 
at  the  summits  of  the  highest  mountains.     It  is  formed  by  the 
combustion  of  substances  which  contain  carbon,  and  by  the 
respiration  of  animals.     When  it  is  formed  in  low  situations,  it 
is  likely  to  accumulate  and  form  an  atmosphere  which  is  com- 
monly known  as  the  choke-damp.     This  is  almost  instantly 
fatal  to  every  animal  placed  in  it.     At  the  Grotto  del  Cane,  in 
Italy,  it  issues  directly  from  the  earth. 

3.  This  gas,  when  in  solution  in  water,  forms  a  pleasant  and 
useful  stimulant  to  the  stomach.     Many  mineral  waters  owe 
their  efficacy,  in  part,  to  this  substance;  this  too  imparts  that 
liveliness  to  the  different  fermented  liquors. 

GENUS  II.    MURIATIC  ACID. 

1.  LIQUID  MURIATIC  ACID. 

Amorphous  and  transparent.  Colour  green  or  greenish. 
Taste  strongly  acid.  Odor  pungent  and  suffocating.  Sp. 
gr.1.27. 

1.  The  natural  form  of  this  substance  is  a  gas,  which  is 
colourless  and  transparent.     It  has  a  strong  affinity  for  water, 
which  causes  it  to  appear  like  a  white  cloud  when  disengaged 
from  its  combinations.     It  consists  of 

Chlorine     37,  one  p. 
Hydrogen     1,  one  p.     "£$ 

2.  It  usually  occurs  in  the  vicinity  of  active  volcanoes,  as 
Mount  ./Etna  and  Vesuvius. 

GENUS  III.    SULPHURIC  ACID. 

I.  LIQUID  SULPHURIC  ACID.    Jam. 

Colourless.    Taste  strongly  acid.  Sp.  gr.  1.850.    Berz. 

1.  It  reddens  litmus  and  the  other  vegetable  blues.  It  acts 
strongly  on  vegetable  and  animal  matter,  even  when  greatly 
diluted. 


ARSENIOUS   ACID,  41 

It  has  a  strong  affinity  for  water.     The  sulphuric  acid  of 
commerce  freezes  at  — 15°  F.    It  is  composed  by  weight  of 
Sulphur  16,  one  p. — Oxygen  24,  three  p. 

2.  The  sulphuric  acid  as  found  in  nature  is  far  from  being 
pure.  Those  acidulous  springs  which  are  found  in  the  neigh- 
borhood of  volcanic  mountains,  contain  free  sulphuric  acid. 
Sulphuric  acid  is  sometimes  produced  also  by  the  decomposi- 
tion of  iron  pyrites,  and  vegetable  matter — as  the  trunks  of 
trees,  leaves,  &c.  with  which  it  comes  in  contact,  are  con- 
verted into  co#Z,  (or  what  is  commonly  called  lignite.)  This 
effect  may  be  observed  on  the  lignite  beds,  a  few  miles  south 
of  South-Amboy. 

GENUS  IV.    BORACIC  ACID. 

1.  PRISMATIC  BORACiC  ACID. 

Baseline,  or  Native  Boracic  Acid.    Jam. 

Colour  grayish  and  yellowish-white.  Streak  white* 
Feebly  translucent.  Taste  acidulous,  afterwards  bitter  and 
cooling — lastly  sweetish.  Sp.gr.  1.48.  Berzelius.  Pri- 
mary form  an  octahedron,  whose  dimensions  have  not 
been  accurately  determined. 

1.  Boracic  acid  fuses  in  the  flame  of  a  candle  and  yields  a 
glassy  globule,  which  acquires  resinous  electricity  by  friction 
on  being  insolated.     Moks.     It  dissolves  freely  in  hot  alcohol, 
and  when  the  solution  is  set  on  fire  it  tinges  the  flame  green. 
It  consists  of  Boron       8,  one  p. 

Oxygen  16,  two  p. 
Water     18,  two  p. 

2.  It  is  deposited  from  the  water  of  the  hot  springs,   near 
Sasso,  in  Tuscany  ;  it  occurs  likewise  at  Volcano,  one  of  the 
Lipari  Islands.     When  crystallized  it  is  pure,  except  an  acci- 
dental admixture  of  sulphur. 

GENUS  V.    ARSENIOUS  ACID. 

1.  OCTAHEDRAL  ARSENIOUS  ACID. 

Oxide  of  Arsenic.    Jam.     drsenious  Add. 

Colour  white.  Often  inclining  to  yellow.  Streak  white.1 
Lustre  vitreous-adamantine.  Semi-transparent.. .opake. 
Sp.  gr.  3.69.  Taste  sweetish..  Astringent.  Mohs. 
Cleavage  parallel  to  the  planes  of  the  regular  octahedron. 
Cross  fracture  conchoidal. 


42  GLAUBER-SALT. 

1.  When  exposed  to  heat  it  volatilizes  and  emits  the  odour 
of  garlic.  The  vapor  may  be  condensed  by  cold,  when  the 
acid  appears  again  in  the  form  of  an  octahedron.  It  is  soluble 
in  water.  It  is  well  known  to  be  the  most  poisonous  substance 
in  nature.  It  is  usually  associated  with  the  ores  of  cobalt, 
lead,  bismuth,  &c.  It  frequently  occurs  in  reniform,  botryoi- 
dal  and  stalactitic  forms,  or  in  thin  crusts  or  scales,  of  a  pear- 
ly lustre.  It  occurs  in  most  of  the  mining  districts  of  Europe. 

ORDER  IV.     SALT. 
GENUS  I.    NATRON-SALT. 

1.  HEMI-PRISMATIC  NATRON-SALT. 

Prismatic  Natron.    Jam. 
Carbonate,  of  Soda.     Phil. 

Taste  mildly  alkaline.  Colour  white.  When  gray  or 
yellow  it  is  owing  to  foreign  admixture.  Lustre  vitreous. 
Hardness  1.0 — 1.5.  Sp.gr.  1.2 — 2.9.  Massive  and 
crystallized.  Primary  form  a  rhombic  octahedron. 

1.  Natron  effervesces  with  the  mineral  acids.     When  ex- 
posed to  air  it  effloresce?.     It  is  composed  of 

Carbonic  acid  22,  one  p. 
Soda  32,  one  p. 

Water  90,  ten  p. 

2.  The  native  carbonate  of  soda  occurs  abundantly  in  Egypt, 
nea«r  certain  lakes  called  Natron  Lakes.   Their  waters  contain- 
ing this  salt  in  solution,  during  the  summer  evaporate  and 
deposito  it  in  a  solid  form.    This  deposite  is  broken  and  packed 
in  casks  and  sent  to  the  European  markets.     It  is  likewise 
found  on  the  surface  of  the  soil  on  the  plains  of  Debreczin  in 
Hungary;  also  in  Bohemia,   Italy,  and  other  European  coun- 
tries.    It  is  found  too  in  the  ashes  of  most  sea-weeds,  particu- 
larly the  Salsola  and  Salicornia. 

3.  This  salt  is  chiefly  employed  in  the  manufacture  of  hard- 
soap  and  glass.     It  is  useful  in  dyeing  and  bleaching. 

GENUS  II.    GLAUBER-SALT. 

1.  PRISMATIC  GLAUBER-SALT. 

Prismatic  Glauber-Sail.     Jam. 
Sulphate  of  Soda.    Phil.     C. 

Colour  white,  grayish  or  yellowish-white,  Lustre  vitre- 


NITRE-SALT.  43 

ous.  Streak  white.  Transparent.  Taste  bitter  and  saline. 
Hardness  1.5 — 2.0.  Sp.  gr.  2.2 — 2.3.  Primary  form  a 
rhombic  octahedron. 

1.  Sulphate  of  soda  effloresces  on  exposure  to  air.   It  is  very 
soluble  in  warm  or  cold  water.     When  exposed  to  heat  it  rea- 
dily undergoes  watery  fusion.     It  is  composed  of 
Sulphate  of  soda  72,  one  p. 
Water  90,  ten  p. 

2.  This  salt  is  found  in  many  lakes  in  Austria,Lower  Hungary, 
Siberia,  Russia  and  Switzerland.  It  sometimes  occurs  in  ef- 
florescences on  old  plastered  walls.  It  is  used  principally  as 
a  cooling  purgative. 

GENUS  III.    NITRE-SALT.         *K/ 

1.  PRISMATIC  NITRE  SALT.y^WyX 

Prismatic  Nitre.    Jam.      fef^ 
Mire,  Nitrate  of  Potash:    Phil.  &  C. 

Colour  white.  Transparent.. .translucent.  Streak  white. 
Lustre  vitreous.  Taste  slightly  saline,  cool,  and  lastly  al- 
kaline. Brittle.  Hardness  2.0.  Sp.gr.  1.93. 

1.  Nitre  deflagrates  when  thrown  on  burning  coals  and 
burns  with  a  pink-red  flame.     It  dissolves  easily  in  water  and 
is  but  little  altered  on  exposure  to  air.     It  forms  a  detonating 
compound  with  combustible  substances. 

2.  This  useful  substance   occurs  in  many  places  in  the 
United  States ;  in  the  caves  where  animal  matter  has  undergone 
decomposition.     In  Kentucky,  Madison  county,  there  is  a  cave 
1936  feet  long  and  40  feet  broad,  which  contains  nitre  in  mix- 
ture with  earthy  matter  and  nitrate  of  lime.     The  nitre  is  ob- 
tained pure  by  mixing  the  compound  with  wood-ashes  and  then 
subjecting  it  to  lixiviation.     From  one  bushel  of  earth  is  ob- 
tained from  three  to  ten  pounds  of  nitre.     It  is  said  to  be  found 
in  some  parts  of  Kentucky,  in  loose  masses,  which  weigh  sev- 
eral pounds. 

3.  Nitre  does  not  occur  in  sufficient  abundance  to  meet  the 
demands  for  it  in  the  purposes  of  life.     It  is  employed  in  the 
manufacture  of  gun-powder,  and  for  making  nitric  acid.     Be- 
sides this,  it  is  used  in  medicine,  and  for  preserving  meat  and 
other  perishable  articles. 


44  ROCK-SALT. 

GENUS  IV.    ROCK-SALT. 

1.  HEXAHEDRAL  ROCK-SALT. 

Common  Salt.    Phil. 
Muriate  of  Soda.     C. 

Colour  generally  white,  passing  into  yellow,  flesh-red 
and  ash-gray.  Transparent.. .translucent.  Lustre  vitreous, 
somewhat  inclining  to  resinous.  Streak  white.  Rather 
brittle.  Hardness  2.0.  Sp.  gr.  2.25.  Taste  saline.  It 
yields  a  perfect  cleavage  parallel  to  all  the  planes  of  the 
cube.  The  solid  angles  are  sometimes  replaced  by  tangent 
planes. 

1.  The  rock  salt  of  Cheshire,  England,   contains  in  1000 
parts,  983£  muriate  of  soda,  6J  sulphate  of  lime,  0.3-16  of  mu- 
riate of  magnesia,  0.3-16  of  muriate  of  lime,  and  10  of  insolu- 
ble matter.     Henry.     Muriate  of  soda  consists  of 

Muriatic  acid  37,  one  p. 
Soda  32,  one  p. 

Rock-salt  is  usually  massive,  but  sometimes  occurs  in  imi- 
tative forms,  as  columnar,  dentiform,  &c.  Fracture  usually 
presents  granular  concretions. 

2.  This  substance  is  abundant.     It  forms  about  one-thir- 
tieth part  of  the  waters   of  the  ocean.     It  occurs  too  in  beds 
and  veins  in  the  earth,  which  are  associated  pretty  constantly 
with  gypsum.    These  beds  are  sometimes  superficial,  as  those 
of  Africa,  or  at  very  great  depth,  as  those  of  Poland.    In  Spain, 
large  isolated  masses  occur  on  the  surface  of  the  earth. 

3.  As  yet  no  beds  of  salt  are  known  within  the  limits  of  the 
United  States.     Numerous   salt-springs  however  exist,  from 
which  are  made  more  than  a  million  of  bushels  of  salt  annual- 
ly.    It  is  worthy  of  notice,  that  these  springs  are  situated  in 
the  interior  of  the  country,   at  a  distance  from  the  sea-coast 
and  from  the  ordinary  course  of  navigation.     Salt-springs  are 
found  in  the  states  of  New-York,  Virginia,  Kentucky,  Ohio 
and  Illinois. 

4.  The  uses  of  common  salt  are  too  well  known  to  require  a 
particular  notice. 


EPSOM-SALT.  45 

GENUS  V.    BORAX-SALT. 

1.    PRISMATIC  BORAX-SALT. 

Prismatic  Borax.    Jam.    Borax.    Borate  of  Soda.    P. 
Bi-Boratc  of  Soda.    Turner. 

Colour  white,  inclining  to  blue  or  green.  Transparent, 
or  translucent.  Streak  white.  Taste  alkaline.  Hardness 
1.5.  Sp.  gr.  1.71.  Cleavage  parallel  to  the  planes  of  an 
oblique  rhombic  prism  of  86°  30'  and  93  °30',  and  indis- 
tinct, in  directions  parallel  to  both  its  diagonals. 

1.  Before  the  blow-pipe  borax  intumesces  and  melts  into  a 
transparent  colourless  bead.      When  dissolved   in  sulphuric 
acid  and  alcohol  it  burns  with  a  green  flame. 

According  to  Thompson,  pure  borax  consists  of 
Soda  33,   one  p. 

Boracic  acid    48,   two  p. 
Water  72,  eight  p. 

2.  Borax  is  brought  principally  from  Thibet,  in  an  impure 
state.     It  is  procured  from  the  borders  of  certain  lakes  whose 
waters  are  impregnated  with  this  salt.     It  is  brought  to  Europe 
in  the  form  of  brown  or  grayish  masses,  in  which  state  fit  is 
called  Tincal.   It  is  said  also  to  occur  in  Ceylon,  and  in  Potosi, 
South  America. 

3.  Borax  is  used  as  a  flux  in  the  production  of  artificial  gems ; 
in  the  process  of  soldering,  and  in  medicine  as  an  external  ap- 
plication. 

GENUS  VI.    EPSOM-SALT. 

1.   PRISMATIC  EPSOM-SALT. 
Sulphate  of  Magnesia.    Phil.    C. 

Colour  white.  Streak  white.  Transparent.. .translucent. 
Lustre  vitreous.  Brittle.  Hardness  2.0.  Sp.  gr.  1.75. 
Taste  saline  and  bitter.  Slightly  efflorescent  on  exposure 
to  air;  crystallizes  in  irregular  six-sided  prisms.  Primary 
form  a  right  rhombic  prism,  the  angles  of  which  are  90°  30' 
and  89°  30.'  Brooke. 

1.  Epsom-salt  is  soluble  in  an  equal  weight  of  water  at  60°. 


46  AMMONIAC-SALT. 

When  exposed  to  heat,  it  undergoes  watery  fusion.     The  com- 
position of  the  pure  salt  may  be  stated  thus  : 

Sulphate  of  magnesia  60,  one    p. 

Water  63,  seven  p. 

2.  It  is  generally  the  product  of  decomposition,  as  it  is  found 
in  efflorescences  on  rocks  in  their  original  repositories,  or  on 
the  exterior  of  plastered  walls.  It  forms  a  principal  ingredient 
in  certain  mineral  waters. 

GENUS  VII.    AMMONIAC-SALT. 

1.  OCTAHEDRAL  AMMONIAC- SALT. 

Octahedral  Sal  Ammoniac.    Jam. 
Muriate  of  Ammonia.     Phil.     C. 

Colour  generally  white,  inclining  to  gray,  yellow  or 
green.  Transparent. ..translucent.  Lustre  vitreous,  faint. 
Hardness  1.5—2.0.  Sp.  gr.  1.52.  Taste  sharp  and  pungent. 
Yields  to  mechanical  division  parallel  to  the  planes  of  a 
cube. 

The  massive  varieties  occur  in  the  form  of  stalactites, 
or  botryoidal,  globular  or  reniform  concretions,  and  some- 
times in  the  form  of  a  mealy  efflorescence. 

1.  The  composition  of  this  substance,  from  Mount  Vesuvius, 
was  found  to  be 

Muriate  of  ammonia,  99.5. 

Muriate  of  soda^  0.5.     Klaproih* 

Sal  ammoniac  occurs  in  cracks  and  fissures  in  the  immediate 
vicinity  of  active  volcanoes,  and  is  the  product  of  sublimation. 
Its  localities  are  Mount  -Etna,  Vesuvius,  the  Solfateras,  and 
the  Lipari  Islands. 

2.  This  salt  occurs  only  sparingly  in  nature.     It  is  therefore 
principally  formed  artificially  by  various  chemical  processes. 
It  is  employed  in  dyeing,  medicine,  and  in  several  operations 
in  metallurgy. 

2.  MASCAGNIN.    Karsten. 
Sulphate  of  Ammonia. 

Colour  yellowish  inclining  to  gray.  Taste  sharp  and 
bitter.  Regular  forms  unknown. 


ALUM-SALT.  47 

When  triturated  with  lime,  it  is  decomposed,  and  the  ammo- 
nia escapes  in  the  form  of  a  pungent  gas.  It  consists  of 

Ammonia  17,  one  p. 

Sulphuric  acid   40,  one  p. 

Water  27,  three  p. 

It  occurs  in  the  vicinity  of  volcanoes,  forming  yellowish 'crusts 
on  the  lava  and  ejected  stones. 

GENUS  VIII.    ALUM  SALT. 

1.  OCTAHEDRAL  ALUM-SALT. 

Octahedral  Mum.    Jam.    Alum.    P. 
Sulphate  of  illumine  and  Potash.    C. 

Colour  white.  Streak  white.  Transparent.. .translucent. 
Lustre  vitreous.  Hardness  2.0 — 2.5.  Sp.gr.  1.75.  Taste 
sweetish,  astringent.  Pure  alum  crystallizes  in  regular 
octahedrons,  the  solid  angles  of  which  are  often  replaced. 
Fracture  conchoidal  with  smooth  surfaces. 

1.  In  nature,  alum  is  never  pure.  It  is  usually  formed 
from  the  decomposition  of  aluminous  rocks,  which  contain 
pyrites,  hence  it  contains  iron  and  other  impurities.  It  consists 
of 

•^ ''  -        Sulphuric  acid  and  water,  77.00. 
Potash,  0.25. 

Oxide  of  iron,  7.50.     Klaproth. 

It  dissolves  easily  in  water  ;  and  melts  before  the  blow-pipe  in 
its  water  of  crystallization,  and  is  converted  into  a  spungiform 


2.  NATIVE  SODA-ALUM. 

Colour  white.  Transparent... translucent.  Lustre jpearly. 
Structure  fibrous.  Sectile.  Brittle.  Hardness  2.0.  Sp. 
gr.  1.88.  Form  prismatic. 

1:  One  hundred  parts  of  water  at  62°  dissolve  377.3  parts. 
Boiling  water  dissolves  an  indefinite  quantity.  When  exposed 
to  air,  it  loses  its  water  of  crystallization  and  becomes  opake. 
Under  the  influence  of  heat  it  appears  like  common  alum.  It 
consists  of  Sulph.  acid,  4  atoms. 

Alumina,       3     do. 

Soda,  1     do. 

Water,       20    do,     Thompson. 


48  BRYTHENE  SALT. 

The  difference  between  the  native  soda  alum  and  the  artificial 
soda  alum  is,  that  the  former  contains  only  20  atoms  of  water, 
and  the  latter  25.  This  is  supposed  to  occasion  a  difference 
in  the  shape  of  the  crystalline  forms.  Thompson. 

3.  DAVITE. 

Sulphate  of  Alumine. 

Colour  white,  greenish,  or  yellowish-white.  Taste  nause  • 
ous  and  highly  astringent.  Lustre,  as  observed  on  a  recent 
fracture,  pearly.  Regular  forms  unknown. 

1.  This  substance,  on  being  subjected  to  the  action  of  the 
blow-pipe,  first  gives  off  its  water  of  crystallization,  and  after- 
wards its  sulphuric  acid,  which  may  be  known  by  its  suffocating 
odour.  It  changes  the  vegetable  blues  to  red.  It  is  composed 
of  Sulphate  of  alumine,  38.0. 

Sulphate  of  iron,  2.4. 

Free  sulph.  acid,          4.6. 

Water,  51.8. 

GENUS  IX.    BRYTHENE*  SALT. 

1.  PRISMATIC  BRYTHENE  SALT. 
Glauberite.    Jam.    Phil.    C. 

Colour  yellowish  or  grayish-white.  Semi-transparent... 
translucent.  Brittle.  Hardness  2. 5. — 3.0.  Sp.gr.  2.80. 
Taste  saline3  feeble.  Lustre  vitreous.  Fracture  conchoi- 
dal.  Cleavage  perfect,  parallel  to  the  planes  of  an  oblique 
rhombic  prism.  P  on  M  or  M',  104°  15'.  M  on  M1 83° 
30'.  Brooke. 

1.  Prismatic  brythene  salt  consists  of 

Sulphate  of  lime,  49.0. 

Sulphate  of  soda,  51.0.     Brogniart. 

It  consists  of  one  atom  of  anhydrous  sulphate  of  lime,  and 
one  atom  of  anhydrous  sulphate  of  soda.  If  immersed  in  water 
it  loses  its  transparency  and  is  partly  dissolved. 

2.  It  occurs  imbedded  in  rock-salt  at  Villarubia,  Spain  ;  like- 
wise in  Aussee,  in  Upper  Austria. 

The  following  earthy  and  alkaline  salts  are  but  little  known, 
*From  brithus  dense  (heavy.)  .«> 


SULPHATE   OF   POTASH.  4? 

1.  SULPHATE  OF  POTASH. 

Colour  white,  yellowish  or  grayish.  Streak  white. 
Transparent.. .translucent.  Rather  brittle.  Lustre  vitreous, 
inclining  to  resinous.  Hardness  2.5. — 3.0.  Sp.gr.  1.73. 
Taste  saline,  bitter,  disagreeable. 

1.  It  consists  of  Sulphuric  acid,  45.93. 

Potash,  54.07.     Berzelius. 

It  occurs  at  Mount  Vesuvius. 

2.  BLffiDITE.    Leonhard. 
Sulphate  of  Magnesia  and  S»da. 

Colour  between  flesh-red  and  brick-red.  Translucent, 
becoming  white  by  decomposition.  Lustre  vitreous,  faint. 
Structure  fibrous.  Fracture  splintery,  soft,  massive,  com- 
posed of  thin  columnar  concretions. 

1.  It  is  composed  of  Sulphate  of  magnesia,  36.66. 

Sulphate  of  soda,          33.34. 

Muriate  of  soda,  22.00. 

Water,  0.34.  Johns. 

It  occurs  at  Ischel,  in  Upper  Austria,  along  with  prismatic 
gypsum,  and  polyhalite. 

3.  POLYHALITE  *     Stromeyer. 

Colour  smoky  and  pearl-gray,  brick  or  flesh-red,  from 
the  presence  of  iron.  Lustre  resinous  or  pearly.  Brittle. 
Fracture  splintery.  Structure  columnar,  compact.  Hard- 
ness 3.5. — 4.0.  Sp.  gr.  2.77.  The  compact  variety  yields 
a  cleavage  parallel  to  the  planes  of  a  cube.  Taste  saline 
and  bitter. 

1.  In  the  flame  of  a  candle  it  melts  into  an  opake  globule. 
When  exposed  to  air  it  is  slightly  efflorescent.  It  consists,  ac- 
cording to  Stromeyer,  of 

Sulphate  of  potash,       27.70. 

Anhydrous  sulph.  lime,  44.74. 
Do.        magnesia,  20.63. 

Muriate  of  soda,  0.19. 

Water,  5.95. 

Peroxide  of  iron,  0.33. 

*From  the  Greek,  signifying  manj  saltf. 

5 


50  NITRATE  OF  SODA. 

4.  NITRATE  OF  SODA. 

Nitrate  of  Soda.     Mariano  de  Rivero.  Ann.  des  Mines. 

Colour  white.  Streak  white.  Transparent.  Rather  sec- 
tile.  Fracture  conchoidal.  Surface  smooth.  Lustre  vitre- 
ous. Hardness  1.5. — 2.0.  Sp.  gr.  2,09.  Taste  bitter  and 
cooling.  It  has  a  perfect  cleavage  parallel  to  the  planes  of 
the  rhombohedron  of  106°  33'. 

1.  When  thrown  on  burning  coals  it  deflagrates,  but  not  so 
actively  as  prismatic  Nitre-salt.     By  friction  it  acquires  strong 
negative  electricity.    Efflorescent  when  exposed  to  air.     It  is 
soluble  in  three  times  of  its  weight  of  water  at  60°. 

2.  It  occurs,  according  to  Mariano  de  Rivero,  in  beds  of 
clay,  in  Peru,  near  the  seaport  of  Yquique,  which  are  said  to 
extend  more  than  fifty  miles.    It  sometimes  appears  in  efflor- 
escences on  the  surface  of  the  earth. 

5.  GAY  LUSSITE.    Boussingault. 

Colour  white.  Transparent... translucent.  Opake  by  de- 
composition. Brittle,  and  easily  reduced  to  powder.  Lustre 
vitreous.  Hardness  1.5. — 2.0.  Sp.  gr.  1.92. — 1.95. 
Fracture  conchoidal.  It  possesses  double  refraction  in  an 
eminent  degree.  Taste  alkaline,  mild. 

1.  Gay  Lussite  decrepitates  before  the  blow-pipe  and  melts 
into  an  opake  globule.  In  nitric  acid  it  dissolves  with  effer- 
vescence, and  if  left  to  partial  spontaneous  evaporation,  crystals 
of  nitrate  of  soda  are  formed  which  float  in  a  solution  of  nitrate 
of  lime.  It  occurs  disseminated  in  clay  in  several  places  in 
Colombia,  S.  A.  It  resembles  Selenite. 

6.  NITRATE  OF  LIME. 

Colour  white,  yellowish-white  or  grayish-white.  Taste 
bitter  and  pungent.  Form  prismatic,  or  undetermined. 

1.  It  occurs  in  silken  tufts,  or  in  delicate  needles,  or  in  a 
pulverulent  form.  Deliquescent.  When  thrown  on  burning 
coals  it  emits  slight  detonations  somewhat  similar  to  nitre. 
Soluble.  It  is  found  on  old  walls  from  decomposition,  or  on 
calcareous  rocks  in  the  vicinity  of  which  animal  matter  has  de- 
composed. 


VITRIOL   SALT.  51 

GENUS  X.    VITRIOL-SALT. 

1.  RHOMBOIDAL  VITRIOL.     Jam. 
Green  Vitriol.    Sulphate  of  Iron.    Phil.    C. 

Colour  green,  yellowish-green.  By  partial  decomposi- 
tion it  becomes  yellowish-white.  Streak  white.  Brittle. 
Hardness  2.0.  Taste  astringent,  metallic.  Primary  form 
an  oblique  rhombic  prism.  P  on'M,  or  M'  99°  20'.  M 
on  M'  82°  20'.  Brooke. 

The  compound  varieties  are  stalactitic,  botryoidal  and 
reniform,  and  sometimes  pulverulent. 

1.  It  consists  of  Protoxide  of  iron      36,  one  p. 

Sulphuric  acid        40,  one  p. 

Water  54,  six  p. 

Those  varieties  which  are  of  a  yellowish-white,  are  anhydrous. 
Green  vitriol  is  easily  soluble  in  water,  and  the  solution  becomes 
black  on  being  mixed  with  a  solution  or  tincture  of  galls. 

2.  This  salt,  in  most  cases,  is  the  product  of  decomposition  ; 
hence  it  occurs  in  connexion  with  iron  pyrites.  The  sulphur  of 
the  pyrites  taking  oxygen  from  the  atmosphere  is  converted  into 
sulphuric  acid,  and  acting  on  the  oxide  of  iron  produces  the  salt 
in  question. 

This  fact  has  taught  us  to  manufacture  this  article  extensive- 
ly in  those  places  where  its  elements  are  found. 

2.  PRISMATIC  VITRIOL.     Jam. 

Blue  Vitriol   Sulphate  of  Copper.     Phil.     C. 

Colour  sky-blue,  in  different  degrees  or  shades.  Streak 
white.  Semi-transparent... translucent.  Opake  by  partial 
decomposition.  Fracture  conchoidal.  Primary  form  an 
oblique  rhombic  prism.  Cleavage  imperfect,  in  the  direc- 
tion of  the  planes  M  and  T.  Hardness  2.5.  Sp.  gr.  2.21. 
Taste  astringent  and  metallic. 

Blue  vitriol,  like  the  preceding  salt,  is  the  result  of  decom- 
position, and  of  course  occurs  in  the  vicinity  of  those  metallic 
deposits  which  contain  its  elements,  as  the  pyramidal  Copper 
pyrites.  It  consists  of 


52  VITRIOL   SALT. 

Oxide  of  copper,    32.14. 

Sulphuric  acid,      31.30. 

Water,  36.30.    BerzeUus. 

This  salt  when  moistened  and  rubbed  on  polished  iron  leaves  a 
trace  of  metallic  copper. 
It  is  used  in  dyeing  and  in  printing  cotton  and  linen,  &c. 

3.  PYRAMIDAL  VITRIOL.    Jam. 

White  Vitriol.    Prismatic  Vitriol- Salt.  Mobs. 
Sulphate  of  Zinc.     Phil.     C. 

Colour  white.  Streak  white.  Transparent.. .translucent. 
Brittle.  Lustre  vitreous.  Hardness  2.0 — 2.5.  Sp.  gr. 
2.03.  Taste  astringent,  metallic.  It  crystalizes  in  four, 
sided  rectangular  prisms.  Primary  form,  right  rhombic 
prism. 

Compound  varieties  are  reniform,  botryoidal  and  sta- 
lactitic.  Sometimes  granular,  passing  into  an  impalpable 
powder. 

1.  It  consists  of  Oxide  of  zinc,  27.5. 
Sulph.  acid,  20.0. 
Water,  50.  Klaprolli. 

The  sulphate  of  zinc,  or  white  vitriol  of  commerce,  is  produced 
in  the  same  way  as  the  sulphates  of  iron  and  copper.  It  is  em- 
ployed as  an  active  emetic  in  medicine ;  but  its  principal  use 
is  in  dyeing. 

4.  RED  VITRIOL. 

Sulphate  of  Cobalt.     Phil. 

Colour  pale  rose-red.  Semi-transparent.. .translucent. 
Lustre  vitreous.  Form  prismatic.  Taste  astringent. 

Compound  varieties  are  coralloidal  and  stalactitic ; 
friable. 

It  is  soluble  in  water.     To  borax,  before  the  blow-pipe,  it 
communicates  a  blue  colour.     It  consists  of 
Oxide  of  cobalt,        38.71. 
Sulph.  acid,  19.74. 

Water,  41.55.     Kopp. 

It  occurs  in  the  rubbish  of  old  cobaltic  mines. 


GYPSUM.  5$ 

5.  SULPHATE  OF  URANIUM.    John. 
Colour  emerald-green.      Lustre  vitreous,  transparent... 
opake.    Brittle.     Soluble  in  water,  and  is  said  to  crystal- 
ize  in  flat  prisms. 

6.  SUB-SULPHATE  OF  URANIUM.    John. 

Colour  bright  sulphur-yellow.  Friable  and  partly  solu- 
ble in  water. 

The  two  last  species  occur  in  the  Uranium  mines  at  Joa- 
chimsthal,  in  Bohemia. 

CLASS  II. 

ORDER  I.     HALOIDE. 
GENUS  1.    GYPSUM-HALOIDE. 

1.   PRISMATOltiAL  GYPSUM-HALOIDE. 


Axi  frangible,  Gypsum. 
Sulphate  of  Lime.    Phil.     C. 

Colour  generally  white,  sometimes  inclining  and  pass- 
ing into  flesh-red,  ochre-yellow,  smalt-blue,  and  gray  of 
different  shades.  Impure  varieties,  dark-gray,  brick-  red 
and  tinged  brownish-red.  Streak  white.  Transparent... 
translucent.  Sectile.  Hardness  1.5.  —  2.0.  The  lowest 
degree  on  the  plane  P.  Sp.gr.  2.31.  Thin  laminae 
flexible  but  not  elastic.  Lustre  pearly.  Primary  form  a 
right  oblique  angled  prism.  Cleavage  perfect,  parallel  to 
the  plane  P.  Inclination  of  P  on  M  or  T  90°.  M  on  T 
113°  08'. 

Compound  varieties  numerous  ;  consisting  of  granular, 
fibrous,  compact  and  earthy  forms.  The  white  compact 
variety  is  the  alabaster  ;  the  fibrous  variety  possesses  a 
pearly  lustre,  and  passes  into  coarse  columnar. 

1.  Gypsum  before  the  blow-pipe  exfoliates  and  melts  into 
a  white  enamel,  which  after  a  few  hours  falls  to  powder.  With 
a  smaller  particle  of  fluor  than  of  gypsum,  it  fuses  easily  and 

5* 


54  GYPSUM. 

combines,  and  the  compound  is  converted  into  a  colourless 
transparent  bead,  which  on  cooling  assumes  the  appearance  of 
a  white  enamel.  BerzeKus. 

Gypsum  is  composed  of 

Lime  28,  one  p. 

Sulph.  acid  40,  one  p. 
Water          18,  two  p.     Thompson. 
The  compound  varieties  sometimes  contain  a  few  per  cent 
of  carbonate  of  lime,  iron,  &c. 

2.  The  crystalized  varieties  occur  mostly  disseminated  in 
argillaceous  deposites  ;  they  are  thus  found  near  Hudson,  in 
the  state  of  New- York. 

3.  The  compound  varieties  of  this  species  form  beds  in  secon- 
dary deposites.     These  beds  are  quite  limited  in  length  and 
breadth.     Its  associations  are  with  the  compact  limestone  and 
sandstone,  as  principal  deposites ;  and  with  rock  salt  and  marly 
clay  as  accompanying  deposites.     These  deposites  contain  or- 
ganic remains  of  extinct  species  of  terrestrial  quadrupeds,  as 
at  Montmartre,   near  Paris. 

4.  Gypsum  is  found  abundantly  in  Nova-Scotia,  large  quan- 
tities of  which  are  imported  into  the  United  States  ;  it  occurs 
also  at  Niagara,  near  the  falls,  and  at  Manlius  and  Lockport, 
in  the  state  of  New- York, 

5.  Gypsum  is  employed  in  the  manufacture  of  artificial  mar- 
ble, stucco  work,  and  hard  mortar  or  finish.     The  finest  white 
variety  is  employed  in  sculpture,  under  the  name  of  alabaster. 
Ground   and  spread  on  certain  soils  it  is  highly  valuable  as  a 
manure. 

2.  PRISMATIC  GYPSUM-HALOIDE. 
Prismatic  Gypsum,  or  Anhydrite.    Jam. 
Anhydrous  Sulphate  of  Lime.    C. 

Colour  generally  white,  sometimes  ash-gray,  ilesh-red, 
violet,  smalt,  and  pale  sky-blue.  Streak  grayish-white. 
Translucent... opake.  Brittle.  Lustre  of  the  crystalized 
varieties  more  distinctly  pearly  than  vitreous.  Hardness 
3.0. — 3.5.  Sp.  gr.  2.89.  Cleavage  parallel  to  the  planes 
of  a  rectangular  prism,  differing  but  little  from  the  cube. 
Most  distinct  and  easy  parallel  to  P. 


CRYONE. 


55 


M 


P  on  M  or  T      90°  0'.    H. 

Mon  T  90  0 

Mon  d  140  4 

T  on  d  129  56 


Compound  varieties. — These  admit  of  the  same  dis- 
tinctions as  those  under  axifrangible  gypsum.  The  con- 
fused crystalized  variety  is  usually  called  sparry  anhy- 
drite. It  is  composed  of  plates  either  parallel  or  contort- 
ed. Others  are  fibrous,  granular  and  compact — in  the  lat- 
tter  the  fracture  is  splintery. 

1.  The  anhydrite  before  the  blow-pipe  does  not  melt  distinct- 
ly, but  becomes  coated  with  a  white  friable  enamel.     It  con- 
sists, according  to  Thompson,  of 

Lime  28,  one  p. 

Sulphuric  acid    40,  one  p. 

It  sometimes  contains  one  per  cent  of  muriate  of  soda,  from 
which  circumstance  it  has  been  called  muriacite. 

2.  The  geological  relations  of  the  anhydrite  are  the  same  as 
in  the  preceding  species.     The  different  varieties  may  be  found 
at  Lockport,  in  the  state  of  New- York  ;  and  generally  in  the 
geodiferous  lime-rock,   associated  with  calc.  and  pearl  spar, 
yellow  blende,  &c.     The  varieties  which  are  compact,  possess 
a  firm  composition,   and  are  polished  for  various   ornamental 
purposes.     It  is  sometimes  called  vulpinite  /  a  small  per  cent 
of  silex  is  usually  found  in  it. 

GENUS  II.     CRYONE-HALOIDE. 

1.  PRISMATIC  CRYONE-HALOIDE. 
Cryolite.     Phil. 
Prismatic  Cry  one.    Jam. 

Colour  white,  sometimes  verging  upon  red  or  yellow- 
ish-brown. Translucent... opake.  Hydrophanous.  Lustre 
vitreous,  inclining  to  pearly.  Brittle.  Hardness  2.5.— 
3.0.  Sp.  gr.  2.96.  '  Cleavage  perfect,  parallel  to  all 
the  planes  of  a  rectangular  prism. 

Compound  varieties, — Massive.  Composition  coarsely 
granular. 


56  FLUOR. 

Cryolite  consists  of 

Alumine,  21.0. 

Soda,  32.0. 

Fluoric  acid  and  water,        47. 

Before  the  blow-pipe  on  charcoal,  this  mineral  fuses  into  a 
transparent  globule,  which  becomes  opake  on  cooling.  With 
borax  it  fuses  into  a  transparent  glass,  and  when  cold  it  be- 
comes milk-white. 

It  occurs  at  West-Greenland,  and  is  yet  a  scarce  substance. 
It  is  geologically  connected  with  gneiss,  or  slaty  granite. 

GENUS  III.     ALUM-HALOIDE. 

1.  RHOMBOHEDRAL  ALUM-HALOIDE. 

Rhomboidal  Mum-Stone.     Jam. 
Alum-Stone.    Phil. 

Colour  white,  sometimes  reddish  or  grayish.  Streak 
white.  Transparent.. .translucent.  Brittle.  Hardness  5. 
Sp.  gr.  2.64.  Lustre  vitreous,  inclining  to  pearly,  upon 
the  more  distinct  faces  of  cleavage.  Primary  form  an 
obtuse  rhomboid  of  the  following  dimensions  : 

P  on  F     92°50'.     P  on  P'  or  P"  87°  11'. 

The  obtuse  solid  angles  are  sometimes  replaced. 

1.  Before  the  blow-pipe  it  first  decrepitates  :  by  a  continu- 
ance of  the  blast  a  sulphurous  gas  is  emitted.  If  it  is  now 
placed  on  the  tongue  it  imparts  a  strong  taste  of  alum.  If  the 
heat  is  continued  till  the  sulphurous  odour  ceases,  it  does  not 
melt,  but  becomes  insipid. 

It  consists  of  alumine,  39.65  ;  sulphuric  acid,  35.49  ;  potash, 
10.02  ;  water  and  loss,  14.83. 

It  occurs  in  a  secondary  rock  at  Tolfa. 

It  is  used  in  the  manufacture  of  alum,  and  the  superior 
quality  of  that  produced  at  Tolfa  is  ascribed  to  the  employ- 
ment of  this  mineral.  Mohs. 

GENUS  IV.    FLUOR. 

I.   OCTAHEDRAL  FLUOR.     Jam. 
Fluor.     Fluatc  of  Lime.    Phil.     C. 

Colour  generally  violet-blue  or  emerald  and  pistachio- 
green,  rose-red  and  crimson-red ;  rarely  white  or  black. 
Streak  white.  Transparent.. .translucent.  Brittle.  Hard- 
ness 4.0.  Sp.gr.  3.14.  Lustre  vitreous.  Cleavage 
perfect,  parallel  to  the  planes  of  the  regular  octahedron. 


FLUOR. 

2. 


57 


5. 


6. 


Compound  varieties. — Massive.  Composition  colum- 
nar or  coarsely  fibrous,  passing  into  compact,  with  a  flat 
conchoidal  fracture.  Columnar  varieties  rarely  curved. 
Colours  often  appear  in  zones. 

1.  Octahedral  fluor  consists  of 

Lime  28,  one  p. 

Fluoric  acid     18,  one  p. 

or  a  compound  of  1  atom  of  fluorine  10.+1  atom  of  calcium  20. 
Before  the  blow-pipe  fluor  decrepitates  and  melts  into  an 
opake  globule.  Its  powder  effervesces  when  thrown  into 
warm  sulphuric  acid,  and  the  vapour  which  escapes  possesses 
the  property  of  corroding  glass. 

Most  varieties  phosphoresce  when  placed  on  a  hot  shovel. 
Those  specimens  which  exhibit  a  bright-green  colour,  are 
called  chlorophanes. 

2.  Fluor  never  forms  a  part  of  the  rocky  strata.     It  is  usu- 
ally associated  with  deposites  of  lead,  zinc  and  silver,  both  in 
beds  or  veins.    It  is  found  in  all  the  rock  formations,  as  primi- 
tive, transition  and  secondary.     Most  of  the  countries  in  Eu- 
rope produce  the  different  varieties  of  fluor. 

3.  It  is  found  green  at  Putney,  Vt.  ;  purple  at  Southamp- 
ton, Mass,  and  white  or  colourless  at  various  places  in  the 
geodiferous  lime  rock  in  New-York,  and  perfectly  black  in 
the  county  of  Genessee,  N.  Y. 

2.  RHOMBOHEDRAL  FLUOR-HALOIDE. 

Rhombohedral  Apatite.    Jam. 
Apatite.    Phosphate  of  Lime.    Phil.     C. 
Colours  white,  yellow,   gray,   red  and  brown.    Fre- 
quently violet-blue,  mountain-green,  or  asparagus-green* 


58 


FLUOR. 


Transparent.. .translucent.  Lustre  vitreous,  inclining  to 
resinous.  Brittle.  Hardness  5.0.  Sp.  gr.  3.22.  Cleavage 
imperfect  and  difficult,  parallel  to  the  planes  of  a  regular 
hexahedral  prism,  which  is  considered  as  the  primary 
form.  This  prism  is  often  terminated  by  six-sided  pyra- 
mids. In  the  annexed  figure  the  pyramid  is  incomplete. 


M  on  P        90° 

M  on  M  120 

x  on  P  140  47' 

x  on  M  129  13     TrootL 


Compound  varieties. — These  belong  in  part  to  the  imi- 
tative forms,  as  the  globular,  reniform  and  the  imperfectly 
columnar.  It  is  sometimes  massive,  and  then  the  com- 
position is  granular,  either  coarse  or  fine,  and  passing  into 
an  impalpable  powder. 

1.  Rhombohedral  Fluor  consists  of 

Lime  28,  one  p. 

Phosphoric  acid    28,  one  p. 

It  dissolves  slowly  in  nitric  acid  without  effervescence.  Some 
varieties  phosphoresce  on  hot  coals.  When  exposed  to  a  strong 
heat  on  charcoal,  the  corners  of  the  fragment  are  rounded,  but 
it  does  not  melt  without  addition. 

2.  This  substance  belongs  to  the  older  rocks,  as  granite 
gneiss  and  mica  slate.     The  hexahedral  prism  truncated  on 
the  terminal  edges,  as  in  the  figure,  occurs  at  Chester,  Ms.  and 
at  St.  Anthony's  nose,  near  New- York.     It  may  also  be  found, 
though  it  is  scarce,  in  most  of  the  granitic  veins  in  N.  England. 

Phosphate  of  lime  occurs  too  at  Topsham,  Me.      West 


LIME.  59 

Marlborough,  Chester  co.  Pa.  at  West  Farms,  at  Warwick, 
Orange  co.  N.  Y.  and  at  Milford  Hills,  Ct. 

3.  PRISMATIC  FLUOR-HALOIDE. 

Herderite.    Haidinger. 

Colour  yellow  or  greenish-white.  Streak  white.  Trans- 
lucent. Lustre  vitreous,  inclining  to  resinous.  Brittle. 
Hardness  5.0.  Sp.  gr.  2.98. 

1.  Prismatic  fluor  occurs  in  the  tin  mines  of  Saxony,  asso- 
ciated with  octahedral  floor.  (Rare.) 

GENUS  V.  LIME-HALOIDE. 
1.  PRISMATIC  LIME-HALOIDE. 

Prismatic  Limestone.    Arragonite.    Jam. 
Arragonilc.    Phil.     C. 

Colour  white,  sometimes  passing  into  gray,  yellow, 
mountain-green  and  violet-blue.  Lustre  vitreous,  as  observ- 
ed on  cleavage*planes,  or  cross-fracture.  Transparent... 
translucent.  Streak  grayish-white.  Brittle.  Hardness 
3.5—4.0.  Sp.  gr.  2.93.  Doubly  refractive.  Yields  to 
cleavage  parallel  to  the  planes  of  a  right  rhombic  prism 
of  1160  5' and  63o  55' 

Compound  varieties. — They  are  commonly  composed 
of  individuals,  disposed  in  coralloidal  and  columnar 
forms ;  the  former  are  beautifully  white,  and  come  principal- 
ly from  Eisenerz  in  Stiria,  and  Hiittenberg  in  Carinthia. 
The  latter  occur  not  only  in  parallel  columns,  but  likewise 
in  radiated  masses ;  in  both  cases  the  individuals  vary  much 
in  size.  Some  are  large  while  others  are  so  small  as  to 
be  discerned  with  difficulty. 

1.  Arragonite  is  composed,  according  to  Stromeyer,  of 
Carbonate  of  lime,  ^       95.29—99.29. 
Carbonate  of  strontian,     0.50 —  4.10. 
The  latter  substance  is  not  constant,  but  it  is  remarked  that 
the  purest  varieties  contain  it  in  the  greatest  proportions.     To 
the  presence  of  carbonate  of  strontian  is  attributed  the  peculiar 
crystalline  form  of  arragonite.     But  it  appears  from  recent  in- 


60 


LIME. 


vestigations  in  crystallography,  that  simple  bodies  are  capable 
of  assuming  at  least  two  distinct  forms  ;  hence  it  may  be  infer- 
red that  the  presence  of  strontian  does  not  modify  the  dimen- 
sions of  the  simple  forms  of  this  substance.  Notwithstanding 
the  relation  which  prismatic  lime-haloide  bears  to  rhombohedral 
lime  in  chemical  composition,  it  is  still,  for  good  reasons,  con- 
sidered a  distinct  species.  Its  form,  hardness,  and  specific 
gravity,  vary  essentially  from  rhombohedral  lime. 

2.  Prismatic  Lime-haloide  occurs  at  Weir's  cave,  Va.  Suck- 
asunny  mine,  N.  J.  Ball's  cave,  and  Foxe's  creek,  Schoharie 
co.  N.  Y.  The  coralloidal  variety  is  sometimes  found  in  the 
geodiferous  lime  rock  in  the  state  of  N.  Y. 

2.  RHOMBOHEDRAL  LIME-HALOID.E. 

Limestone.    Jam.     Carbonate  of  Lime.    Phil.     C. 

Colour  of  the  pure  varieties,  white.  Impure  and  mixed 
varieties,  different  shades  of  gray,  red,  green,  yellow,  and 
sometimes  dark-brown  and  black.  Streak  white  and  gray- 
ish-white. Transparent... translucent.  Lustre  vitreous. 
Double  refraction  very  distinct  and  easily  observed.  Brit- 
tle. Hardness  3.0.  Sp.gr.  2.72.  Cleavage  perfect,  parallel 
to  the  planes  of  a  rhomboid  of  the  following  dimensions  : 
Obtuse  angles,  or  P  on  P'  or  P"  105°  5'.  Acute  angles 
74°  55'. 


Fig.  1. 


Fig.  2. 


Fig.  3. 


M 


M. 


Fig.  1 .    The  primary  form,  which  is  an  obtuse  rhomboid. 

Fig.  2.  A  regular  hexahednal  prism  formed  by  (he  omission  of  a  single  row 
of  particles  along  the  lower  edges  of  the  rhomb. 

Fig.  3.  is  a  dodecahedral  crystal,  formed  by  the  omission  of  two  rows  of 
particles  along  the  same  edges  as  in  the  preceding  figure. 

Count  Bournon  has  described  56  modifications  of  the  rhomboid  of  carbonate 
of  lime,  and  other  mineralogist!  hare  greatly  increased  the  number, 


LIME.  61 

Compound  massive  varieties. — They  have  a  composition 
both  granular  and  compact.  Individuals,  in  some  instan- 
ces, are  sufficiently  large  to  exhibit  the  internal  structure 
of  the  species.  In  others,  they  are  so  small  as  to  become 
imperceptible  ;  the  mass  then  assumes  a  compact  structure, 
and  is  known  under  the  name  of  compact  limestone. 
Other  compositions  are  columnar.  When  the  individuals 
are  thin  and  closely  aggregated,  the  mineral  is  known 
under  the  name  of  satin  spar,  or  fibrous  carbonate  of  lime. 
Under  favorable  circumstances  the  external  forms  are 
imitative,  as  stalactical,  tuberose,  botryoidal,  and  co- 
ralloidal :  surfaces  rough  and  dull,  frequently  dr,usy, 
and  internally  they  are  made  up  of  distinct  layers,  either 
parallel,  curved  or  divergent. 

1.  Carbonate  of  lime  burns  to  quick-lime  before  the  blow- 
pipe, and  effervesces  with  the  mineral  acids.     It  consists  of 

Carbonic  acid  22,  one  p. 
Lime  28,  one  p. 

2.  Rhombohedral  Lime-haloide  is  distributed  extensively  in 
nature,  and  in  such  great  quantities  that  it  composes  l-5th  of 
all  the  rock  formations.      Sometimes  it  forms  considerable 
masses  or  beds  in  other  rocks.     The  white  granular  varieties 
belong  to  primitive  formations,  while  the  dark  compact  belong 
to  the  transition  and  secondary  formations.     Several  other  va- 
rieties of  limestone  form  extensive  deposites,  and  are  distin- 
guished by  particular  names — thus,   Oolite  or  roe-stone,  con- 
sists of  roundish  grains  which  internally  exhibit  columnar  in- 
dividuals, disposed  like  the  radii  of  a  sphere.     Pea-stone,  or 
pisolite,  resembles  in  form  and  composition  the  oolite,  but  each 
globule  is  formed  around  a  particle  of  sand.     Chalk  is  a  spe- 
cies of  compact  limestonje  whose  particles  possess  only  a  fee- 
ble coherence.    Rock-milk,  or  agaric  mineral,  has  considerable 
resemblance  to  chalk,  but  the  particles  are  much  more  loose 
and  friable.     Calcareous  tufa,  is  a  recent  deposite  from  the 
water  of  springs,  which  contain  carbonate  of  lime  in  solution. 
Swinestone,  marl  and  bituminous  limestone,  are  mixed  and  im- 
pure varieties  of  rhombohedral  Lime. 

3.  Several  of  the  preceding  varieties  are  extensively  used 
for  various  purposes.    Those  employed  in  sculpture  and  orna- 

6 


62  LtME. 

mental  architecture,  are  called  marbles.  These  are  prized  and 
valued  according  to  pureness,  colour,  translucency,  and  the 
size  and  aggregation  of  their  particles.  When  polished  they 
form  the  most  durable  of  all  materials  for  sculpture  and  build- 
ing. A  peculiar  fine  grained  variety  is  employed  in  forming 
plates  for  lithographic  printing.  Carbonate  of  lime  when  free 
from  intermixture  of  siliceous  particles,  forms  good  quick-lime 
by  burning.  It  is  likewise  useful  as  a  flux,  for  smelting  the 
ores  of  iron.  When  burned  into  quick-lime  it  enters  into  the 
composition  of  mortar.  It  forms  for  some  soils  a  valuable  ma- 
nure. 

1.  Sub-  Species.    ARGENTINE. 

Colour  pure  white  ;  sometimes  greenish  or  reddish.  Trans- 
lucent... opake.  It  is  composed  of  thin  slaty  individuals  which 
are  generally  undulating  or  curved.  Surfaces  smooth,  or  dru- 
sy.  The  slaty  particles  often  intersect  each  other  so  as  to  form 
cavities,  which  are  often  studded  with  crystals  of  rhombohedral 
quartz.  Lustre  pearly,  eminent. 

It  occurs  in  beds  and  veins  in  primitive  rocks.  In  Goshen 
and  Southampton,  Mass,  it  is  found  in  granite. 

2.  APHRITE.     Jam. 

Colour  white.  Streak  white.  Lustre  pearly.  Cleavage  mo- 
notonous. Composition  granular,  scaly,  slightly  coherent. 
Opake.  Feels  soft.  Soils  a  little.  Hardness  0.5.  —  1.0.  Sp. 
gr.  2.53. 

1.  Effervesces  in  the  mineral  acids  and  completely  dissolves. 
When  friable,  it  absorbs  water  readily. 

It  consists  of    lime,  51.50. 

Carbonic  acid,  39.00. 
Silex,  5.71. 

Oxide  of  iron,     3.28. 
Water,  1.00. 

3.  MACROTYPOUS*  LIME-HALOIDE. 

Bitter  Spar.    Pearlspar.    .Dolomite. 
Magnesian  Limestone.    Phi!.     C. 

Colour  seldom  pure  white  except  the  compound 
lar  varieties,  but  generally  inclines  to  red  or  green. 
grayish-white.   Semi-transparent...  opake.  Brittle.   Hard- 

*  From  makros,  long,  and  tnpos,  the  form, 


Streak 


LIME.  63 

ness  3.5. — 4.0.     Sp.  gr.  2.88.     Cleavage  perfect,  parallel 
to  the  planes  of  a  rhomboid  of  106°  15'. 

Compound  massive  varieties. — They  are  usually  granu- 
lar, individuals  often  sufficiently  large  to  exhibit  the  struc- 
ture of  the  species.  Forms  sometimes  imitative,  as  glob- 
ular, botryoidal  and  fruticose,  whose  surfaces  are  often 
drusy.  Composition  rarely  columnar ;  when  columnar, 
the  variety  is  called  miasite.  The  granular  variety  is 
known  under  the  name  of  dolomite,  and  is  often  friable, 
or  only  slightly  coherent. 

1.  Macrotypous  Lime-haloide,  is  a  carbonate  of  lime  and 
magnesia.     The  relative  quantity  of  its  elements  are  found  to 
vary.   According  to  Rlaproth  it  consists  of  30.56  lime,  22.18 
magnesia,  47.26  carbonic  acid  ;  hence  it  consists  of  two  atoms 
of  carbonic  acid,  one  atom  of  lime,  and  one  atom  of  magnesia. 

2.  The  present  species  is  soluble  in  the  mineral  acids  with 
effervescence,  but  not  so  rapidly  as  the  preceding  species. 
Before  the  blow-pipe  it  often  assumes  a  darker  colour,  and  be- 
comes harder.     It  phosphoresces  by  friction  with  hard  bodies, 
with  a  yellowish-white  light. 

Dolomite  occurs  abundantly  in  nature  ;  it  enters  extensively 
into  rock-formations  and  frequently  prevails  over  extensive  dis- 
tricts. It  is  easy  to  mistake  it  for  the  granular  variety  of  rhom- 
bohedral  lime.  It  is  more  frequently  associated  with  talcose 
slate,  steatite,  serpentine,  8fc.  It  occurs  in  Middlefield,  Cum- 
mington,  Williamstown,  Pittsfield,  Adams,  Windsor,  Hins- 
dale,  Sheffield,  and  Gt.  Barrington,  Mass. ;  Newfane  and 
Marlborough,  Vt. ;  Washington,  Milford  Hills,  and  Litchfield, 
Ct. 

4.  BRACHYTYPOUS*  LIME-HALOIDE. 

Carbonate  of  Magnesia  and  Iron.    Phil. 

Colour  generally  inclining  to  yellow,  also  white  and 
brown.  Streak  grayish-white.  Translucent.,  .opake.  Lus- 
tre vitreous,  inclining  to  pearly  on  the  faces  of  cleavage • 
Brittle.  Hardness  4.0. — 4.5.  Primary  form  a  rhombohe- 

*  From  brachus,  short,  and  tupos,  form. 


64  LIME. 

dron,  whose  planes  incline  to  each  other  at  angles  of  107° 
22 '.     Cleavage  perfect. 

v  1.  This  mineral  is  composed  of  carbonate  of  magnesia  and 
carbonate  of  iron.  According  to  H.  J.  Brooke,  Esq.  it  con- 
sists of  1.315  carb.  iron,  8.605  carb.  magnesia,  without  a 
trace  of  lime. 

It  is  found  in  the  Tyrol,  in  single  crystals  of  a  yellow  colour, 
imbedded  in  talc  or  chlorite.  Phil.  This  mineral  is  abundant 
in  New  Fane  and  Marlborough,  Vt.  imbedded  in  a  grayish- 
green  steatite. 

5.  PARATOMOUS*  LIME-HALOIDE. 

Colour  white  with  various  tints  of  gray,  red,  and  brown. 
Streak  white.  Translucent,  often,  only  faintly.  Brittle. 
Hardness  3.5. — 4.0.  Sp.  gr.  3.08. 

Before  the  blow-pipe  it  becomes  black,  and  magnetic.  It 
dissolves  with  brisk  effervescence  in  the  mineral  acid.  The 
colour  becomes  dark  on  long  exposure  to  the  air.  The  chem- 
ical constitution  of  this  species  is  not  well  ascertained.  The 
principal  constituents  are  carbonate  of  lime  and  carbonate  of 
magnesia.  It  is  deposited  on  mica  slate  in  the  Rathausberg  in 
Salzburg. 

It  forms  an  excellent  addition  in  the  process  of  smelting  iron 
ores. 

GENUS  I.    WAVELLINE-HALOIDE. 

1.  PRISMATIC  WAVELLINE-HALOIDE. 

Wavellite.    Sub-phosphate  of  Alumine.    Phil. 

Colour  white,  passing  into  several  shades  of  green, 
gray,  brown  and  black.  Translucent.  Hardness  3. 5.  Sp. 
gr.  2.3.  Primary  form  a  right  rhombic  prism,  M  on  M' 
about  122°  15'.  Cleavage  perfect,  parallel  to  the  planes 
M  and  M'  and  to  the  longer  diagonal.  Lustre  of  those 
planes  intermediate  between  pearly  and  vitreous. 

Compound  varieties  consist  of  implanted  globules  com- 
posed of  thin  columnar  individuals  radiating  from  a  com- 
mon centre. 

*  From  para  about,  and  ttmno,  I  cletve. 


LIME.  65 

1.  Before  the  blow-pipe  on  charcoal  it  intumesces,  loses  its 
crystaline  form,  and  becomes  snow-white.  Withboracicacid 
and  iron  it  gives  a  fused  product  of  phosphuret  of  iron.  Berz. 

Wavellite  is  composed  of  alumina  35.35,  phosphoric  acid 
33.40,  fluoric  acid  2.06,  lime,  oxides  of  iron  and  manganese 
1.75,  water  26.60.  It  was  first  discovered  by  Dr.  Wavel,  in 
or  near  Barnstable,  in  Devonshire,  Eng. 

GENUS  I.    ORTHOKLASE-HALOIDE. 

1.  PRISMATOTDAL  ORTHOKLASE-HALOIDE. 

Hopeite.     Brewster.     Trans.  R.  Soc.  Ed. 

Colour  grayish-white.  Streak  white.  Transparent... 
translucent.  Lustre  vitreous.  Surface  often  striate.  Re- 
fraction double.  Sectile.  Hardness  2.5. — 3.0.  Sp.  gr. 
2.76. 

1.  Before  the  blow-pipe  it  melts  easily  into  a  clear  colour- 
less globule,  which  tinges  the  flame  green.     Fused  with  soda, 
it  gives  a  yellow  scoria  while  hot,  and  copious  floccoli  of  zinc 
and  some  cadmium  are  deposited  near  the  scoria.     The  melted 
mineral  forms  a  fine  blue  glass,  with  a  solution  of  cobalt. 

2.  Hopeite  resembles  stilbite,  for  which  it  had  been  mista- 
ken.    It  is  considered  as  a  compound  of  some  of  the  stronger 
acids,  as  phosphoric  or  boracic  acid,   zinc  and  an  earthy  base, 
with  a  little  cadmium  and  a  large  quantity  of  water. 

It  has  been  found  only  at  the  calamine  mines  of  Altenberg, 
near  Aix-la-chapelle.  (Rare.) 

The  following  species  have  not  as  yet  received  scientific 
names  ;  their  places  in  the  systematic  arrangement  of  minerals 
are  not  satisfactorily  determined,  and  some  of  them  are  but 
little  known. 

1.  MAGNESITE. 

Carbonate  of  Magnesia. 

Colour  white,  grayish  or  yellowish  white.  Opake,  or 
only  feebly  translucent.  Lustre  pearly  or  dull.  Hard- 
ness ranges  between  1. — 3.9.  Sp.  gr.  2.8. 

Compound  varieties. — Long  capillary  crystals,  either 
parallel  or  diverging  ;  sometimes  in  mamillary  concre- 
tions, whose  surfaces  are  covered  with  delicate  crystaline 

6* 


6fr  LIME. 

tufts.     Massive  varieties  are  granular  and  compact,  often 
passing  into  pulverulent,  impalpable. 

1.  In  the  mineral  acids  it  dissolves  with  effervescence  and 
forms  soluble  compounds,  which  are  usually  bitter. 
It  consists  of    Magnesia  20,  one    p. 

Carbonic  acid    22,  one    p. 
Water  27,  three  p. 

It  is  found  at  Hoboken,  N.  J.  in  horizontal  veins,  traversing 
a  soft  serpentine. 

2.  ROSELITE. 

RoseliU  Levy.     Ann.  of  Phil,  xlvii.  p.  4,  39. 
Edinburgh  Jour,  of  Science,  vol.  ii.  p.  177. 

Colour  deep  rose-red.  Streak  white.  Translucent. 
Hardness  3.0.  Primary  form  a  right  rhombic  prism. 
Cleavage  perfect,  parallel  to  the  plane  P. 

1.  Before  the  blow-pipe,  it  gives  off  water  and  becomes 
black.  .To  borax  and  salt  of  phosphorus  it  imparts  a  fine  blue 
colour.  In  muriatic  acid  it  dissolves  without  residue. 

Roselite  is  composed  of  cobalt,  lime,  arsenic  acid  and  mag- 
nesia, in  proportions  not  well  determined. 

3.  FLUELTJTE. 

FluelKlc  of  Wallaston.    Levy.    Ann  of  Phil.  Oct.  1824,  p.  241. 

Colour  white.    Transparent. 

1.  It  occurs  in  minute  crystals  which  affect  the  form  of  a 
scaline  four-sided  pyramid,  with  most  of  its  acute  solid  angles 
replaced.  It  is  associated  with  the  Wavellite  from  Cornwall. 

4.  CHILDRENITE. 

ChUdrenile.  Brooke.  Brande's  Q.  J.  v.  xvi.  p.  274. 
Colour  yellowish- white,  wine-yellow,  ochre-yellow  and 
pale  yellowish-brown.  Streak  white.  Translucent.  Lustre 
vitreous,  inclining  to  resinous.  Fracture  uneven.  Hard- 
ness 4.5 — 5.0.  According  to  Dr.  Wollaston,  it  is  a  com- 
pound of  phosphoric  acid,  alumina  and  iron.  (Rare.) 

5.  PHARMACOLITE.    Jam. 
Arseniate  of  Lime.     Phil. 

Colour  white.  Translucent.. .opake.  Lustre  vitreous. 
Pearly  in  the  thin  columnar  particles.  Sectile.  Very  soft, 
Sp.  gr.  2.G4  Klaprotk. 


BARYTE.  67 

Compound  varieties  occur  in  globular,  reniform  and 
botryoidal  masses,  which  are  composed  usually  of  thin  co- 
lumnar particles.  Sometimes  it  occurs  in  the  form  of  an 
impalpable  powder. 

1.  Before  the  blow-pipe  it  emits  an  arsenical  odour,  and 
melts  with  difficulty  into  a  white  enamel.     It  dissolves  with 
effervescence  in  nitric  acid.     It  consists  of 

Lime,  25.00. 

Arsenic  Acid,     50.54. 
Water,  24.46. 

2.  It  is  found  at  Andreasberg  in  the  Hartz.     The  picro- 
pliarmacolite  of  Stromeyer,  differs  from  the  above  in  containing 
about  three  per  cent  of  magnesia  and  a  trace  of  cobalt. 

ORDER  II.     BARYTE. 
'GENUS  I.     PARACHROSE*-BARYTE. 

H.=3.5— 4  5. 
G.  =3.3— 3.9. 

1.  BRACHYTYPOUS  PARACHROSE-BARYTE. 

Sparry  Iron.     Jam. 

Spathose  Iron.     Carbonate  of  Iron.     Phil.     C. 

Colour  various  shades  of  yellow,  passing  into  ash  and 
yellowish-gray,  also  into  several  kinds  of  yellow,white,  red 
and  brown,  and  by  long  exposure,  into  black.  Streak  white. 
Translucent  in  different  degrees.  Lustre  vitreous,  inclin- 
ing to  pearly.  Brittle.  Hardness  3.5. — 4.5.  Sp.  gr. 
3.82.  It  yields  to  cleavage  parallel  to  the  planes  of  a 
rhomboid  of  107°  arid  73°.  It  often  occurs  massive,  in 
which  form  there  exists  a  regular  composition. 

1.  Carbonate  of  iron  consists  of 

Carbonic  acid  22,  one  p. 

Protox.  iron      36,  one  p. 

„  Before  the  blow-pipe  it  becomes  black  and  magnetic,  but 
does  not  melt.  i  It  dissolves  slowly  and  with  a  feeble  efferves- 
cense  in  nitric  acid.  When  exposed  to  air  it  changes  colour 
and  disintegrates,  diminishes  in  hardness,  and  finally  passes 
into  the  form  of  a  dark-brown  or  blackish  powder. 

*  Fromparachrofif,  change  of  colour. 


68  BARYTE. 

2.  It  is  found  accompanying  rhombohedral  Lime-haioide  in 
primitive  formations.     It  occurs  abundantly  at  New-Milford, 
Ct.  chiefly  in  foliated  masses,   but  sometimes  in  the  primary 
form  of  the  species. 

3.  Carbonate  of  iron  is  a  valuable  mineral ;  large  quanti- 
ties of  wrought  and  cast  iron  are  obtained  from  it.     Its  great- 
est value  however,  as  an  ore  of  iron,  arises  from  the  facility  of 
converting  it  directly  into  steel. 

2.  MACROTYPOUS  PARACHROSE-BARYTE. 
Rhomboidal  Red  Manganese,    Jam. 
Carbonate  of  Manganese.    Phil.     C. 

Colour  rose  red,  reddish-white  and  brownish.  Lustre 
vitreous,  inclining  to  pearly.  Streak  white.  Translu- 
cent in  different  degrees.  Brittle.  Hardness  3.5.  Sp. 
gr.  3.59.  Cleavage  parallel  to  the  planes  of  a  rhomboid 
of  107°.  Occurs  massive  with  a  granular  composition. 
The  individuals  in  this  case  are  sometimes  small  and  even 
imperceptible. 

1.  Carbonate  of  manganese  consists  of 

Protoxide  of  manganese  36,  one  p. 
Carbonic  acid  22,  one  p. 

The  native  carbonate  often  contains  silex,  oxide  of  iron  and 
lime.  It  effervesces  with  the  mineral  acids.  Before  the  blow- 
pipe its  colour  is  changed  into  gray,  brown  and  black,  and  it 
decrepitates  strongly,  but  does  not  melt  without  addition.  It 
dissolves  in  borax,  which  becomes  violet-blue  or  purple.  The 
rose-red  varieties  on  exposure  to  light  and  air  become  paler. 

It  occurs  in  metalliferous  veins,  associated  with  the  ores  of 
copper,  silver  and  lead. 

GENUS  II.    ZINC-BARYTE. 

H.=5.0 
G.=3.3— 4.5. 
1.  PRISMATIC  ZINC-BARYTE. 

Prismatic  Calamine  or  Electric  Calamine.    Jam. 
Siliceous  Oxide  of  Zinc.    Phil.     C. 

Colour  yellowish,  or  grayish-white  and  light-brown, 
and  sometimes  greenish  and  bluish.  Transparent... trans- 


BARYTE.  6$ 

lucent.  Lustre  vitreous,  inclining  to  pearly  on  the  face* 
of  cleavage.  Brittle.  Hardness  5.0.  Sp.  gr.  3.37. 
Cleavage  perfect,  parallel  to  the  planes  of  a  right  rhombic 
prism,  which  is  the  primary  form.  M  on  P  172°  30'.  M 
on  M'  132°  35'. 

Compound  varieties  occur  in  botryoidal  and  stalactica! 
forms  ;  composition  often  granular  and  columnar.  Some- 
times it  is  compact. 

1.  When  reduced  to  powder  it  dissolves  in  warm  sulphuric 
or  muriatic  acids,  and  when  cold,  it  forms  a  jelly.     Before  the 
blow-pipe  alone  in  the  matrass,  decrepitates  slightly,  gives  off 
water,  and  becomes  milk-white.     Infusible  without  addition. 
With  borax  it  fuses  into  a  colourless  glass.     The  silica  may 
be  made  perceptible  with  a  large  quantity  of  salt  of  phosphorus; 
Phosphorescent  by  friction.     Remarkably  electric  by  heat. 

2.  Siliceous  oxide  of  zinc  consists  of 

Oxide  of  zinc  42,  one  p. 

Si  lex  16,  one  p. 

Water  9?  one  p. 

This  mineral  belongs  principally  to  calcareous  rocks  j  it  is 
usually  associated  with  blende,  carbonate  of  zinc  and  sulphu- 
retoflead.  It  occurs  at  the  Perkiomen  lead  mines,  Pa.  and 
at  Franklin,  N.  J. 

2.  RHOMBOHEDRAL  ZINC-BARYTE. 

Rhombohedral  Calamine.    Jam.     Carbonate  of  Zinc. 
Calamine.     Phil.    C. 

Colour  white,  rarely  pure  ;  frequently  gray,  green  or' 
brown.     Streak  white.     Semi-transparent... opake.    Lus- 
tre vitreous,  inclining  to  pearly.     Brittle.     Hardness  5.0. 
Sp.  gr.  4.44.     Cleavage  perfect  parallel  to  the  planes  of 
a  rhombohedron  of  107°  40'. 

The  compound  varieties  occur  in  reniform,  botryoidal 
and  stalactitic  forms.  It  appears  in  crystaline  coats  in- 
vesting other  minerals.  By  decomposition  it  becomes 
friable. 


70  BARYTE. 

1,  Carbonate  of  zinc  consists  of 

Oxide  of  zinc    42,  one  p. 

Carbonic  acid    22,  one  p. 

It  dissolves  with  effervescence  in  the  mineral  acids.  Before 
the  blow-pipe  in  the  reducing  flame,  it  covers  the  charcoal 
with  zinc  fumes,  but  does  not  fuse. 

2.  Jt  accompanies  the  preceding  species,  and  occurs  at  the 
same  localities.     It  is  found  at  Franklin,  N.  J. 

GENUS  III.    SCHEELIUM-BARYTE. 

H.=4.0— 4.5. 
G.=6.0— 6.1. 

1.  PYRAMIDAL  SCHEELIUM-BARYTE 

Pyramidal  Tungsten.    Jam. 
Tungstate  of  Lime.    Phil.     C. 

Colour  generally  white,  or  passing  into  yellowish-gray, 
orange-yellow,  or  reddish-brown.  Streak  white.  Semi- 
transparent... translucent.  Lustre  vitreous,  inclining  to 
adamantine.  Brittle.  Hardness  4.0. — 4.5.  Sp.  gr. 
6.07.  Yields  to  cleavage  parallel  to  the  planes  of  an  oc- 
tahedron with  a  square  base.  P  on  P'  100°  40'.  P  on 
P"  129°  2'.  Brooke.  Fracture  imperfect  conchoidal. 

The  compound  massive  variety  resembles  the  carbonate 
and  sulphate  of  lead  or  barytes. 

1 .  Pyramidal  scheelium-baryte  consists  of 
Lime,  19.40 

Oxide  of  scheelium,  80.42 

Alone  on  charcoal  it  is  infusible.  With  borax  it  gives  a 
white  glass.  It  generally  occurs  in  those  repositories  (?)  which 
contain  tin,  topaz,  fluor,  quartz,  &c.  It  is  found  at  Hunting- 
ton,  Ct. 

GENUS  IV.    HAL-BARYTE. 

H.=3.0— 3.6. 
G.=3.6— 4.7. 
J.  PERITOMOUS*  HAL-BARYTE. 

Strontian.    Carbonate  of  Slrontian.     Phil.    C. 

Colour  asparagus-green,  or  yellowish-white.     Translu- 

*  Froraperif  round,  and  temno,  I  cleave. 


BARYTE.  71 

cent.  Fracture  splintery.  Lustre  resinous,  pearly  and 
vitreous.  Streak  white.  Brittle.  Hardness  3.5.  Sp. 
gr.  3.60.  Cleavage  perfect,  parallel  to  the  lateral  faces  of 
a  right  rhombic  prism  ;  less  perfect  parallel  to  the  plane 
P.  M  on  MM  17°  32'. 

Compound  varieties  have  a  fibrous  structure  both  paral- 
lel and  divergent.  Lustre  pearly.'  Seldom  granular. 

1.  Before  the  blow-pipe  it  is  infusible  except  on  the  surface, 
but  the  mass  becomes  white  and  opake.     It  intumesces  and 
exhibits  a  brilliant  light.     During  the  blast  the  flame  is  tinged 
faintly  of  a  purplish-red  ;  taste  of  the  fragment  alkaline.     Dis- 
solves with  effervescence  in  the  mineral  acids.     It  consists  of 

Protoxide  of  strontium     52,  one  p. 
Carbonic  acid  22,  one  p. 

2.  This  mineral  occurs  in  metallic,  veins  traversing  primi- 
tive and  transition  mountains,   in  company  with  hexahedral 
Lead-glance,  prismatic  Hal-baryte,  arsenical  pyrites,  quartz, 
&c.     (Rare.) 

2.  DI-PRISMATIC  HAL-BARYTE. 

Rhomboidal  Bafyle  or  Witherite.    Jam. 
Carbonate  of  Baryies.     Phil.     C. 

Colour  generally  yellowish-white,  approaching  orange- 
yellow,  grayish,  greenish  and  rarely  reddish-white.  Semi- 
transparent... translucent.  Streak  white.  Lustre  vitre- 
ous and  shining.  Brittle.  Hardness  3.0 — 3.5.  Sp.  gr. 
4.30.  Fracture  uneven.  Cleavage  imperfect.  Primary 
form  is  supposed  to  be  a  right  rhombic  prism.  M  on  M' 
118°  30'.  The  ordinary  hexagonal  prisms  probably  re- 
sult from  the  intersection  of  three  of  the  primary  crystals. 
Brooke. 

Compound  varieties  are  stalactitic  and  fibrous,  or  thin 
columnar,  passing  into  crystals  of  a  bladed  form. 

1.  Before  the  blow-pipe  it  decrepitates  slightly  and  melts 
easily  into  a  transparent  bead,  which  becomes  opake  on  cool- 
ing. It  dissolves  with  effervescence  in  the  mineral  acids. 


72  BARYTE. 

Di-prismatic  barytes  consists  of 

Prot.  oxide  of  barium     78,  one  p. 
Carbonic  acid  22,  one  p. 

It  occurs  in  veins  traversing  the  metalliferous  limestone  and 
the  primitive  formations,  and  most  generally  associated  with 
lead,  silver,  tin,  &c. 

The  carbonates  of  strontian  and  barytes  are  violent  poisons. 

3.  PRISMATIC  HAL-BARYTE. 

Prismatic  Baryte  or  Heavy  Spar.    Jam. 
Sulphate  of  Baryte.    Phil.    C. 

Colour  generally  white,  sometimes  inclining  to  gray, 
yellow,  blue,  red,  and  brown.  Transparent... opake. 
Streak  white.  Lustre  vitreous,  inclining  to  resinous. 
Brittle.  Hardness  3.0. — 3.5.  Sp.  gr.  4.44.  Cleavage 
parallel  to  the  planes  of  a  right  rhombic  prism,  and  to  the 
short  diagonal.  M  on  M'  101°  42'. 

Compound  varieties  occur  of  various  imitative  shapes, 
as  globular,  reniform  and  stalactical.  Composition  often 
lamellar,  sometimes  fibrous  or  thin  columnar.  The  form- 
er variety  is  known  as  the  lamellar  sulphate  of  barytes  and 
the  latter  as  the  fibrous  sulphate  of  barytes.  It  is  some- 
times granular,  which  graduate  into  impalpable.  Less 
important  varieties  have  been  described. 

1.  Prismatic  Hal-baryte  consists  of 

Protoxide  of  baryum       73,  one  p. 

Sulphuric  acid  40,  one  p. 

Before  the  blow-pipe  it  fuses  with  difficulty  and  decrepitates 
if  heated  suddenly.  It  decomposes  in  the  interior  flame  and 
gives  sulphuret  of  barytes,  which  when  moistened,  exhales  a 
Blight  hepatic  odour.  Taste  hepatic  and  pungent. 

2.  It  accompanies  the  ores  of  lead  and  iron,  and  frequently 
octahedral  fluor. 

The  localities  of  this  mineral  are  numerous.  Southhamp- 
ton,  Hatfield,  Greenfield,  Mass. ;  Berlin,  Farmington,  Hart- 
ford, Southington,  Ct.  ;  Little  Falls,  on  the  Mohawk,  Living- 
ston's lead  mine,  and  Watertown,  N.  Y.  At  the  latter  place, 
in  large  flesh  coloured  masses. 


BARYTE. 


4.  PRISMATOIDAL  HAL-BARYTE. 

Jlxifrangible  Baryte.    Jam. 

Celestine.     Sulphate  of  Strontian.    Phil.     C. 

Colour  usually  white,  passing  into  blueish-gray,  sky- 
blue  and  smalt-blue.  Also  reddish-white  and  flesh-red. 
Transparent... opake.  Brittle.  Hardness  3.0.-— 3.5.  Sp. 
gr.  3.85.  Cleavage  perfect,  parallel  to  the  planes  of  a 
right  rhombic  prism. 

l.  2. 


M 


M 


Fig.  1. Primary  form.    Fig.  2.    Sulphate  of  Strontian,  epointee. 

M  on  M  104°  48' 
O  on  P  128  3 
O  on  O  77  2 
d  on  d  101  32 

Compound  varieties  have  a  structure  both  lamellar  and 
fibrous,  thus  forming  two  distinct  varieties. 

1.  Before  the  blow-pipe  it  decrepitates  and  melts  without 
colouring  the  flame,  into  a  white  friable  enamel.    It  consists  of 

Protoxide  of  strontium       52,  one  p. 
Sulphuric  acid  40,  one  p. 

This  mineral  is  more  frequently  met  with  in  the  secondary 
limestone,  sandstone  and  trap  rocks,  in  globular  and  laminat- 
ed masses  of  various  sizes. 

2,  It  occurs  at  Lockport  and  Moss  Island,  N.  Y.  and  at 
numerous  places  in  the  same  rock  formation,  associated  with 
prismatic  gypsum,  yellow  blende  and  octahedral  fluor. 

5.  BARYTO-CALCITE. 
BarytO'Calcile.    Brooke.    Ann.  of  Phil.  xliv.  p.  114. 

Colour  white,  grayish,  yellowish  or  greenish.  Streak 
white.  Transparent... translucent.  Lustre  as  observed 
on  a  recent  fracture  vitreous,  inclining  to  pearly.  Hard- 

7 


74 


BARYTE. 


ness  4.0.      Sp.  gr.  3.66.      Cleavage  not  very  difficult, 
parallel  to  M,  perfect  parallel  to  P. 


M 

M 

on 

M 

106° 

54' 

P 

on 

M 

102 

54 

C 

b 

on 

b 

95 

15 

\ 

c 

on 

c 

145 

54 

1.  It  consists  of  Carbonate  of  barytes,    65.9. 

Carbonate  of  lime,        33.6.    Children. 

Before  tbe  blow-pipe  it  does  not  melt.  With  borax  it  gives 
a  clear  globule.  Occurs  at  'Alston  Moor,  in  Cumberland, 
Eng.  both  massive  and  crystalized. 

6.  STROMNITE. 
Bary-Slrontianite.     Traill.    Trans.  R.  Soc.  Ed.  vol.  ix.  p.  81. 

Colour  white,  yellowish-white,  grayish-white  after  dis_ 
integration.  Lustre  inclining  to  pearly,  faint.  Translu- 
cent. Brittle.  Hardness  3.5.  Sp.  gr.  3.70.  Massive. 
Composition  thin  columnar. 

1.  Before  the  blow-pipe  it  is  infusible.     Effervesces  with 
acids.     It  consists  of 

Carbonate  of  strontia,  68.6. 
Sulphate  of  baryta,  27.5. 
Carbonate  of  lime,  2.6. 

Oxide  of  iron,  0.1.     Traill. 

2.  It  occurs  in  clay  slate  at  Stromness,  in  Orkney.     A  min- 
eral agreeing  in  many  of  the  characters  of  the  stromnite  is 
found  in  Clinton,  near  Hamilton  college,  N.  Y. 

GENUS  V.    LEAD-BARYTE. 

H.=2.5— 4.0. 
G.=6.0— 7.3. 

1.  DI-PRISMATIC  LEAD-BARYTE. 

Di-Prismatic  Lead-Spar.    Jam. 
Carbonate  of  Lead.    Phil.     C. 

Prevailing  colour  white,  passing  into  yellowish-gray, 


BARYTES.  7$ 

ash-gray  and  smoke-gray.  Sometimes  tinged  blue  or 
green  by  the  carbonate  of  copper.  Streak  white.  Trans- 
parent...translucent.  Brittle.  Lustre  adamantine.  If 
the  colours  are  dark,  the  lustre  is  often  metallic.  Frac- 
ture conchoidal.  Hardness  3.0. — 3.5.  Sp.  gr.  6.46- 
Primary  form  a  right  rhombic  prism.  Cleavage  perfect 
parallel  to  the  plane  P,  M  &  M'  and  to  the  shorter  diagonal, 
but  liable  to  be  interrupted  by  the  conchoidal  fracture. 
M  on  M'  1 17°.  P  on  M  or  M'  90°. 

Compound  varieties. — Composition  granular,  passing 
into  earthy — the  latter  is  known  as  the  earthy  lead  spar. 

1.  Before  the  blow-pipe  it  decrepitates,  becomes  yellow 
and  red,  and  finally  yields  a  globule  of  lead.     It  effervesces  in 
the  mineral  acids  and  is  easily  soluble.     It  consists  of 

Protoxide  of  lead       112,  one  p. 
Carbonic  acid  22,  one  p. 

2.  Occurs  abundantly  in  the  different  mining  districts  of 
Europe.     In  the  United  States,  at  the  Perkiomen  lead  mine, 
and  near  Lancaster,  Pa.    Also,  at  Southampton,  Mass. 

2.  RHOMBOHEDRAL  LEAD-BARYTE. 

Rhomboidal  Lead-Spar.    Jam. 
Arseniate  of  Lead.    Phosphate  of  Lead.    Phil.     C. 

Colour  generally  green  or  brown.  According  to  Mobs, 
there  is  an  uninterrupted  series  of  colours  from  various 
shades  of  white  through  siskin-green,  asparagus-green, 
grass-green,  pistachio-green,  olive-green,  oil-green  ;  wax- 
yellow,  honey-yellow,  orange-yellow ;  aurora-red,  hya- 
cy nth-red ;  pearl-gray  and  ash-gray.  Streak  white,  some- 
times inclining  to  yellow.  Semi-transparent... translu- 
cent on  the  edges.  Brittle.  Hardness  3,5. — 4.0.  Sp. 
gr.  7.09.  Fracture  imperfect  conchoidal.  Lustre  resin- 
ous. Cleavage  parallel  to  all  the  planes  of  the  regular 
eix-sided  prism,  and  also  to  the  planes  C  C'  C",  which 
would  give  a  double  six-sided  pyramid  as  the  primary 


76 


BARYTE. 


form ;  but  the  prism,  being  the  most  simple  solid,  is  se- 
lected as  the  primary  form. 


M  on  M 

P  on  M 

M  or  M'  on  d' 

M  on  c' 

P   on  c  or  c' 

c'  on  c  or  c" 


90 
150 
131 
138 
110 


00 
00 
45 
30 
5 


Compound  varieties  occur  in  botryoidal,  reniform  and 
fruticose  shapes.  Internal  composition  columnar. 

1.  Before  the  blow-pipe  it  melts  by  itself  on  charcoal  and  the 
bead  assumes  a  polyhedral  form  of  a  dark  colour.     If  bo- 
rax is  added  to  the  pulverised  globule,  it  is  partially  reduced. 
It  dissolves  in  warm  nitric  acid  without  effervescence. 

It  consists  of  Protoxide  of  Lead,  112. 
Phosphoric  acid,       28. 
A  trace  of  muriatic  acid  is  usually  found. 

2.  It  occurs  in  the  various  mining  districts  of  England,  in 
the  United  States,  in  the  Perkiomen  lead  mines,  Pa.  and  at 
Southampton,  Mass. 

The  following  analysis  of  specimens,  containing  arsenic 
acid,  exhibits  the  proportions  of  the  elements  forming  those 
varieties. 

Oxide  of  lead,        77.50—77.50. 

Phosphoric  acid,      7.50—00.00. 

Arsenic  acid,          12.00 — 19.00. 

Muriatic  acid,          1.00 — 01.53. 

3.  HEMI-PRISMATIC  LEAD-BARYTE. 

Prismatic  Lead-Spar.    Jam. 
Chromale  of  Lead.    Phil.    C. 

Colour  various  shades  of  hyacinth-red.  Streak  orange- 
yellow.  Translucent.  Sectile.  Lustre  adamantine. 
Hardness  2.5.— 3.0.  Sp.  gr.  6.00.  Fracture  small  con* 
choidal,  uneven.  Cleavage  parallel  to  all  the  planes  of 
an  oblique  rhombic  prism  of  93°  30'  and  86°  30'. 

1.  Before  the  blow-pipe  it  crackles  and  melts  into  a  grayish 
slag.  With  borax  it  is  partially  reduced,  and  gives  to  the  flux 
a  green  colour. 


BARYTE.  77 

|t  consists  of  Protoxide  of  lead  112,  one  p. 
Chromic  acid         52,  one  p. 

2.  It  is  found  in  Siberia  in  the  gold  mine  of  Beresof,  in  a 
vein  traversing  gneiss  and  mica  slate. 

4.  PYRAMIDAL  LEAD-BARYTE. 

Pyramidal  Lead- Spar.    Jam. 
Molybdate  of  Lead.    Phil.    C. 

Prevailing  colour  wax-yellow,  olive-green,  orange-yel- 
low, yellowish-gray  and  grayish- white.  Lustre  resinous. 
Streak  white.  Translucent  on  the  edges.  Structure  per- 
fectly lamellar.  Brittle.  Hardness  3.0.  Sp.gr.  6.7.  It 
yields  to  cleavage  parallel  to  the  planes  of  an  octahedron 
with  a  square  base,  and  also  to  the  common  base  of  the 
two  pyramids.  The  angle  of  one  face  on  the  opposite 
face  over  the  summit  is  49°  45'.  The  inclination  of  P 
on  P"  or  P'  on  P"'  131°  15'.  P  on  P'  99°  50'. 

1.  Before  the  blow-pipe  it  decrepitates,  and  fuses  on  char- 
coal into  a  dark  gray  mass,  in  which  globules  of  lead  are  visi- 
ble.    With  a  little  borax  it  forms  a  brownish  globule  ;  with  a 
large  quantity,  a  blue  or  greenish-blue  glass.     It  consists  of 

Protoxide  of  lead  112,  one  p. 

Molybdic  acid,  containing  oxygen  24        72,  one  p. 
It  generally  contains  1  or  2  per  cent  of  oxide  of  iron. 

2.  It  occurs  at  the  Southampton  lead  mine,  Mass,  and  at 
the  Pekiomen  lead  mine,  Pa.  . 

5.  PRISMATIC  LEAD-BARYTE. 

Tri'Prismatic  Lead-Spar.    Jam. 
Sulphate  of  Lead.    Phil,  and  C. 

Colour  yellowish-gray  and  greenish-white;  also  yel- 
lowish, smoke  and  ash-gray.  Streak  white.  Transpa- 
rent...translucent.  Lustre  adamantine.  Brittle.  Hard- 
ness 2.5.— 3.0.  Sp.  gr.  6.29.  Structure  perfectly  lamel- 
lar. It  admits  of  cleavage  parallel  only  to  the  planes  of 
a  right  rhombic  prism,  which  is  therefore  the  primary 
form.  M  on  M'  103°  42'.  P  on  M  or  M'  90°, 

7* 


78  .         BARYTE. 

Compound  varieties  often  granular,  of  various  sizes  of 
individuals. 

1.  Before  the  blow-pipe  it  decrepitates,  then  melts,  and  is 
soon  reduced  to  a  metallic  state.    It  consists  of 

.  Protoxide  of  lead  112,  one  p. 
Sulphuric  acid       40,  one  p. 

2.  It  occurs  at  the  Southampton  lead  mine,  Mass.,  at  Hun- 
tington,  Con.,  and  at  the  Perkiomen  lead  mine,  Pa. 

6.  AXOTOMOUS  LEAD-BARYTE. 

Sulphato-iri-  Carbonate  of  Lead.     Brooke.    Ed.  Phil.  Jour. 

Colour  yellowish-white,  passing  into  various  shades  of 
gray,  green,  brown  and  yellow.  Streak  white.  Trans- 
parent...translucent.  Hardness  2.5.  Sp.gr.  6.26.  Lus- 
tre resinous,  inclining  to  adamantine.  Cleavage  axoto- 
mous.  Primary  form  an  acute  rhomboid  of  72°  30'  and 
107°  30'. 

Composition  of  the  massive  varieties  lamellar  or  gran- 
ular. 

1.  Before  the  blow-pipe  it  first  intumesces  and  then  becomes 
yellow,  but  reassumes  a  white  colour  on  cooling.  It  efferves- 
ces briskly  in  nitric  acid,  but  leaves  a  white  residue. 

It  occurs  at  the  lead  hills,  in  Scotland,  with  various  other 
ores  of  lead. 

7.  SULPHATO-CARBONATE  OF  LEAD. 
Brooke.    Ed.  Phil.  Jour.  vol.  3.  p.  1 17. 

Colour  greenish  or  yellowish- white.  ,  Streak  white. 
Translucent.  Sfcctile.  Lustre  adamantine,  inclining  to 
pearly  on  a  perfect  face  of  cleavage.  Hardness  2.0. — 2.5. 
Sp.  gr.  6.8. — T.O.  Brooke.  Cleavage  in  two  directions, 
in  one  more  distinct  than  the  other.  Primary  form  a  right 
oblique  angled  prism  of  59°  15'  and  120°  45'.  Crystals 
minute  and  indistinct,  and  variously  aggregated. 

1.  Before  the  blow-pipe  on  charcoal  it  fuses  into  a  globule 
•which  is  white  when  cold,  and  is  nearly  reduced  to  metallic 
lead.  Effervescence  in  nitric  acid  scarcely  perceptible.  It  con- 
niata  of  46.9  of  carbonate  of  lead  and  53.1  of  sulphate  of  lead. 


BARYTE.  79 

2.  It  occurs  at  the  lead  hills  in  Scotland. 

8.  CUPREOUS  SULPHATO-CARBONATE  OF  LEAD. 
Brooke.    Ed.  Phil.  Jour,  vol  3,  p.  117. 

Colour  deep  verdigris-green,  inclining  to  mountain- 
green.  Streak  greenish-white.  Translucent.  Lustre 
resinous.  Fracture  uneven.  Brittle.  Hardness2.5. — 3.0. 
Sp.  gr.  6.3.  It  yields  to  mechanical  division  parallel  to 
the  planes  and  shorter  diagonal  of  a  right  rhombic  prism, 
MonM'95°.  PonM'orM90°. 

1.  It  consists  of  Sulphate  of  lead,        55.8. 

Carbonate  of  lead,     32.8. 

Carbonate  of  copper,  11.4. 
Occurs  at  the  lead  hills,  Scotland. 

9.  CUPREOUS  SULPHATE  OF  LEAD. 
Brooke.    Ann.  of  Phil.  vol.  4,  p.  117. 

Colour  deep  blue,  resembling  the  purest  varieties  of  blue 
carb.  of  copper.  Streak  pale,  blue.  Faintly  translucent. 
Brittle.  Hardness  2.5.— 3.0.  Sp.  gr.  5.30.— 5.43.  Lus. 
tre  adamantine.  Cleavage  parallel  to  the  planes  M  and 
T  of  a  right  rhombic  prism  ;  perfect,  parallel  to  the  for- 
mer. 


MT 

ft 

2 

M  on  T        102°  45' 
P   on  M         90    00 
P   on  T          90    00 
—  on  fi           90    00 
M  on  d         120    80 

1.  It  consists  of  Sulphate  of  lead,  74.4. 

Oxide  of  Copper,  18.0. 

Water,  4.7.    H.  J.  Brooke, 

Occurs  at  the  lead  hills,  Scotland. 

10.  MURIO-CARBONATE  OF  LEAD.    Phil. 

Corneous  Lead.    Jam. 

Colour  white,  exhibiting  occasionally  pale  tints  of  gray, 
yellow  or  green.  Streak  white.  Transparent... translu- 
cent. Lustre  adamantine,  Sectile.  Structure  said  to 


80  BARYTE. 

be  lamellar.     Hardness  2.0.     Sp.  gr.  6.05.     It  yields  to 
cleavage  parallel  to  all  the  planes  of  a  square  prism. 

1.  Before  the  blow-pipe  it  melts  quickly  into  a  yellow  glob- 
ule which  becomes  white,  and  crystalizes  on  the  surface  while 
cooling.     Upon  charcoal  it  is  reduced.     It  consists  of 

Oxide  of  lead,  85.5. 
Muriatic  acid,  8.5. 
Carbonic  acid,  6.0. 

2.  It  is  said  to  occur  at  Southampton  lead  mine,  Mass,  as- 
sociated with  other  ores  of  lead,  fluor  and  barytes. 

11.  PERITOMOUS  LEAD-BARYTE. 

A  new  ore  of  Lead.    Berzelius.    Ann.  of  Phil.  xliv.  p.  154. 

Colour  yellowish-white,  straw-yellow,  rose-red,  pale. 
Fracture  imperfect  chonchoidal.  Translucent.  Lustre 
adamantine.  Brittle.  Hardness  2.5.— 3.0.  Sp.gr.  7.07. 
Haidinger.  Cleavage  perfect  and  easily  obtained  par- 
allel to  a  four-sided  prism  of  102°  27',  with  traces  in  the 
direction  of  the  shorter  diagonal. 

1.  Before  the  blow-pipe  it  decrepitates  slightly  and  is  easily 
melted.    The  globule  becomes  a  deeper  yellow  than  the  miner- 
al.   On  charcoal  it  is  reduced  with  fumes  of  muriatic  acid. 
Treated  with  oxide  of  copper  and  salt  of  phosphorus,  the  flame 
assumes  an  intense  blue  colour. 

2.  Occurs  near  the  Mendip  hills  in  Somersetshire,  Eng. 

12.  PLOMBGOMME. 

Colour  yellowish  and  reddish-brown,  striped.  Translu- 
cent. Hardness  4.5.  Massive;  composition  thin  columnar, 
impalpable. 

1.  If  rubbed  when  insulated,  it  acquires  a  strong  negative 
electricity.     Before  the  blow-pipe  it  decrepitates  and  loses  its 
water,  but  is  infusible  per  se.     With  borax  it  is  not  reduced, 
but  yields  a  transparent  glass. 

It  consists  of  Oxide  of  lead,  40.14. 

Alumina,  37.00. 

Water,  18.80. 

Sulphurous  acid,  0.20. 
Lime  and  the  oxides  of  iron  and  magnesia*  1.80. 

Silica,  0.60. 

2,  Occurs  in  Brittany  in  clay  slate. 


BARYTE.  81 

13.  TUNGSTATE  OF  LEAD. 

Colour  yellowish-gray,  faintly  translucent.  Lustre  res- 
inous. Crystals  acute,  four-sided  pyramids,  much  aggre- 
gated in  bunches. 

1.  Before  the  blow-pipe  it  melts  and  gives  off  vapours  of 
lead,  leaving  a  crystaline  globule  of  a  dark  colour  and  metallic 
aspect,  which  yields  a  pale-gray  powder.     With  soda  it  yields 
a  large  quantity  of  globules  of  lead. 

2.  Occurs  at  Zinnwald,  in  Saxony. 

14.  VANADIATE  OF  LEAD. 

Colour  varies  from  straw-yellow  to  reddish-brown. 
Streak  white.  Brittle.  Fracture  conchoidal.  Lustre 
resinous.  It  is  scratched  by  the  knife.  Sp.  gr.  6.99 — 
7.23.  Primary  form  and  cleavage  unknown.  Crystal- 
izes  in  six-sided  prisms. 

1.  Heated  to  redness  in  a  platina  crucible,   it  decrepitates 
and  becomes  orange  yellow,  but  becomes  pale  as  it  cools.     If 
kept  in  fusion,  mixed  with  charcoal,  it  becomes  steel-gray  and 
globules  of  lead  soon  appear  in  the  mass.      Sulphuric  and  mu- 
riatic acids  decompose  it  and  form  solutions  of  a  green  colour. 
With  nitric  acid  a  yellow  solution  is  formed.     When  the  latter 
acts  upon  it,  the  oxide  of  lead  is  first  dissolved  and  the  re- 
maining fragments  are  coated  with  vanadic  acid,  which  is  of  a 
reddish  colour  and  in  the  form  of  crystaline  grains. 

2.  It  occurs  in  two  forms — one,  is  in  tbeform  of  mamillated 
masses,  composed  generally  of  microscopic  crystals,  but  some- 
times large  enough  to  discover  their  forms,  which  are  six-sided 
prisms.     In  the  other  it  occurs  in  an  impalpable  powder,  like 
calamine  sprinkled  over  the  surface  of  other  minerals,  or  form- 
ing on  them  roundish  pisiform  masses.     Both  forms  somewhat 
resemble  the  earthy  peroxide  of  manganese. 

3.  It  is  found  at  the  lead  mines  of  Zimapan,  in  Mexico,  and 
atWanlockhead,  Scotland,  and  at  Fahlun,  Sweden. 

GENUS  VI.    ANTIMONY-BARYTE. 

H=2.5— 3.0. 

G=5.5— 5.6. 

1.  PRISMATIC  ANTIMONY-BARYTE. 

Prismatic  White  Antimony.    Jam. 
Oxide  of  Antimony.    Phil. 

Prevailing  colour  white,  also   yellowish  or  grayish- 


82  KERATE. 

white,  sometimes  peach  blossom-red.  Streak  white.  Semi- 
transparent... translucent.  Lustre  adamantine.  Sectile. 
Brittle.  Hardness  2.5.— 3.0.  Sp.gr.  5.56.  It  yields  to 
cleavage  parallel  to  the  sides  of  a  rhombic  prism  of  137° 
43'  and  42°  17',  but  the  most  distinct  cleavage  is  parallel 
to  the  shorter  diagonal. 

1.  Before  the  blow-pipe  it  melts  very  easily  and  is  volatil- 
ized in  white  fumes.     It  consists  of 

Antimony,  44. 
Oxygen,        8. 
It  contains  both  a  trace  of  iron  and  silox. 

2.  It  occurs  at  Przibram,  Bohemia,  and  at  Braunsdorf,  in 
Saxony. 

ORDER  III.    KERATE. 
GENUS  I.     PEARL-KERATE.  ^ 

H=  1.0— 2.0. 
S=5.5— 65. 

1.  HEXAHEDRAL  PEARL-KERATE. 

Hexahedral  Corneous  Silver.    Jam. 
Muriate  of  Silver.     Horn  Silver.    Phil.    C. 

Colour  pearl-gray,  passing  on  the  one  hand  into  laven- 
der-blue and  violet-blue,  and  on  the  other  into  grayish- 
yellowish  and  greenish-white,  into  siskin-green,  asparagus, 
green,  pistachio  and  leek-green.  When  exposed  to  the 
light  it  becomes  brown.  Streak  shining.  Translucent. 
Lustre  resinous,  passing  into  adamantine.  Sectile  and  mal- 
leable. Hardness  1.0. — 1.5.  Sp.  gr.  5.55.  Cleavage 
none.  Crystalizes  in  cubes  and  acicular  prisms. 

Composition  of  compound  varieties  granular,  passing 
into  impalpable. 

1.  It  melts  in  the  flame  of  a  candle.  Before  the  blow-pipe 
on  charcoal  it  is  reduced,  giving  off  at  the  same  time  the  va- 
pours of  muriatic  acid.  When  rubbed  with  a  piece  of  moisten- 
ed zinc  it  becomes  coated  with  a  film  of  metallic  silver. 

2.  Occurs  chiefly  in  primitive  rocks,  accompanying  other  ores 
of  silver.  It  is  most  abundant  in  the  silver  mines  of  Potosi,  S. 
America. 


MALACHITE.  83 

It  consists  of  Silver,  67.00. 

Oxygen,  8.00. 

Muriatic  acid,  14.75. 
Oxide  of  iron,  6.00. 
Alumina,  1.75. 

2.  PYRAMIDAL  PEARL-KERATE. 

Pyramidal  Corneous.    Mercury.    Jam. 
Muriate  of  Mercury.    Phil.    C. 

Colour  yellowish-gray  or  ash-gray,  also  yellowish  and 
grayish-white.  Streak  white.  Translucent.  Lustre  ada- 
mantine. Sectile.  Hardness  1.7 — 2.0.  Sp.  gr.  6.48. 
Crystalizes  in  quadrangular  prisms  terminated  by  pyra- 
mids. 

1.  Before  the  blow-pipe  on  charcoal  it  is  "perfectly  volatil- 
ized.    Soluble  in  water,  from  which  it  is  precipitated  by  lime 
water  of  an  orange  colour. 

2.  It  consists  of  Oxide  of  mercury,    88.48. 

Muriatic  acid,  11.52. 

It  occurs  chiefly  at  Moschellandsberg,  in  Deuxponts,  and 
at  Almaden,  in  Spain. 

ORDER  IV.    MALACHITE. 
GENUS  I.    SATPHYLINE*-MALACHITE. 

H=2.0— 3.0. 

G=2. 0—2.2. 

1.  UNCLEAVABLE  STAPHYLINE-MALACHITE. 

Common  Copper-green  or  Chrysocolla.    Jam,    Phil. 

Colour  emerald  green,  pistachio-green,  asparagus-green, 
passing  into  sky-blue.  The  appearance  of  brown  indi- 
cates impurity.  Streak  white.  Semi-transparent... trans- 
lucent on  the  edges.  Hardness  2.0. — 3.0. 

Compound  varieties  occur  in  botryoidal  and  reniform 
shapes.  Structure  compact  and  fibrous,  with  a  choncoidal 
fracture.  Sometimes  earthy. 

1.  Before  the  blow-pipe  it  becomes  black  without  melting* 
With  borax  it  forms  a  clear  green  glass,  mixed  with  particles 

*  From  staphule,  the  grape.  The  varieties  hitherto  known  ustially  present 
hotryoidal  form*. 


84  MALACHITE. 

of  reduced  copper.    It  dissolves  with  effervescence  in  nitric 
acid. 
It  consists  of  Copper,  40.00 — 42.00. 

Oxygen,  10.00—  7.63. 

Silica,  26.00—28.37. 

Water,  17,00—17.50. 

Carbonic  acid,   7.00—  3.00. 

GENUS  II.    LIROCONE*-MALACHITE. 

H=2.0— 2.5. 
G  =2.8— 3.0. 

1.  PRISMATIC  LIROCONE-MALACHITE. 

Di-Prismatic  Olivenitc.    Jam. 
Octahedral  Jlrseniate  of  Copper.    Phil. 

Colour  sky-blue,  verdigris-green.  Streak  similar  to 
the  colour,  paler.  Semi-transparent.. .translucent.  Not 
perfectly  sectile.  Lustre  vitreous,  inclining  to  resinous. 
Hardness  2.0.-- 2.5.  Sp.  gr.  2.92. 

It  yields  to  mechanical  division,  though  with  difficulty, 
parallel  to  all  the  planes  of  a  rectangular  octahedron.  P 
on  F  60°  40'.  M  on  M'  72°  22'.  M  on  P  133°  30'. 

1.  Before  the  blow-pipe  it  loses  its  colour  and  transparency, 
and  emits  arsenical  vapours,  and  is  changed  into  a  friable  scoria 
containing  white  metallic  globules.  With  borax,  it  yields  a 
green  globule  and  is  partly  reduced.  In  nitric  acid  it  dissolves 
with  effervescence.  (Rare.) 

It  consists  of  Oxide  of  copper,  49.00. 
Arsenic  acid,  14.00. 
Water,  35.00. 

2.  HEXAHEDRAL  LIROCONE-MALACHITE. 

Hexahedral  Olivenite  or  Cube  Ore.    Jam. 
Ar&tniate  of  Iron.     Phil.     C. 

Colour  olive-green,  passing  into  yellowish-brown  and 
blackish-brown,  hyacinth-red,  grass  green  and  emerald 
green.  Streak  olive-green... brown,  pale.  Translucent 
on  the  edges.  Lustre  indistinctly  adamantine.  Sectile* 

""From  fcmw,  pale,  andfonw  powder.  ' 


MALACHITE.  85 

Fracture  conchoidal,  uneven.  Hardness  2.5.  Sp.gr.  3.00. 
It  yields  to  cleavage  parallel  to  the  planes  of  the  cube, 
but  difficult  and  imperfect. 

1.  Exposed  to  a  gentle  heat,  it  becomes  red.  On  charcoal, 
before  the  blow-pipe,  it  emits  copious  arsenical  vapors,  and 
melts  in  the  inner  flame  into  a  metallic  scoria,  which  acts  upon 
the  magnetic  needle. 

It  consists  of  Oxide  of  iron,  •  45.50 
Arsenfc  acid,  31.00 
Oxide  of  copper,.  9.00 
Silex,  4.00 

Water,  10.50 

It  occurs  in  Cornwall,  Eng. 

GENUS  III.    OLIVE-MALACHITE. 

H=3. 0—4.0. 
0=3.6—4.6. 

1.  PRISMATIC  OLIVE-MALACHITE. 

Jlcicular  Olivenite.    Jam. 

Right- Prismatic  Jlrseniate  of  Copper.     Phil.     C. 

Colour  various  shades  of  olive-green,  passing  into  leek- 
green,  brown  and  wood-brown.  Streak  olive-green... 
brown.  Lustre  indistinctly  adamantine.  Translucent... 
opake.  Brittle.  Hardness  3.0.  Sp.  gr.  4.28. 

Cempound  varieties  occur  in  globular  and  reniform 
shapes.  Surface  rough  and  drusy.  Composition  colum- 
nar ;  individuals  straight  and  divergent  :  granular  and 
lamellar  :  the  latter  often  curved. 

1.  Before  the  blow-pipe  it  remains  unchanged — with  char- 
coal it  melts  and  is  reduced.  A  white  metallic  globule  is  form- 
ed which  on  cooling  becomes  coated  with  the  oxide  of  copper. 
Soluble  in  nitric  acid. 

It  consists  of  the  Oxide  of  copper,  50.62 
Arsenic  acid,  45.00 
Water,  3.50 

Occurs  in  the  mines  of  Cornwall,  Eng. 

2.  DI-PRISMATIC  OLIVE-MALACHITE. 

Phosphate  of  Copper,     Phil.    C. 

Colour  dark  olive-green.     Streak  olive-green.     Trans- 

8 


86  MALACHITE. 

lucent  on  the  edges.  Lustre  resinous.  Fracture  conchoi- 
dal.  Brittle.  Hardness  4.0.  Sp.  gr.  3.6. — 3.8.  Pri- 
mary form  a  right  rhombic  prism  of  1 10°  and  70°  Cleav- 
age distinct,  parallel  to  the  plane  P — less  distinct  parallel 
to  M  or  M'. 

1.  Before  the  blow-pipe  on  the  first  impression  of  heat  it  fuses 
into  a  brownish  globule,  which  by  further  action  of  the  blow- 
pipe it  extends  on  the  surface  of  the  charcoal  and  acquires  a 
reddish-gray  metallic  lustre  ;  in  the  centre  is  a  small  globule  of 
copper. 

It  consists  of  Oxide  of  copper,   68.13 

Phosphoric  acid,    30.95      Klaproth. 

GENUS.  IV.     AZURE-MALACHITE. 

H=3.5— 4.0. ' 
G=3.7— 3.9. 

1.  PRISMATIC  AZURE-MALACHITE. 

Blue  Copper  or  Prismatic  Malachite.    Jam. 
Blue  Carbonate  of  Copper.    Phil.     C. 

Colour  various  shades  of  azure-blue,  passing  into  berlin- 
blue.  Streak  blue,  pale.  Translucent  on  the  edges.  Lus- 
tre vitreous.  Brittle.  Hardness  3.5 — 4.0.  Sp.  gr. 
3.83.  Fracture  conchoidal.  Structure  lamellar.  Prima- 
ry form  an  oblique  rhombic  prism.  Cleavage  perfect 
parallel  to  the  planes  M  &  M'  and  both  diagonals ;  diffi- 
cult parallel  to  the  plane  P,  which  is  usually  striated. 

Compound  varieties  occur  in  botryoidal,  reniform  and 
stalactitic  shapes,  with  a  composition  more  or  less  colum- 
nar. Rarely  granular  or  earthy. 

1.  Before  the  blow-pipe  on  charcoal  it  melts  and  colours  the 
glass  of  borax  green  in  the  oxidating  flame. 

It  consists  of  Protoxide  of  copper,  72  one  p. 
Carbonic  acid,  22  one  p. 

Water,  9  one  p. 

It  is  met  with  in  veins  accompanying  other  ores  of  copper, 
lead  and  silver. 

It  is  found  at  Southampton,  Mass. ;  Perkiomen  lead  mines, 
Pa. ;  Schuyler's  mines,  N.  J. 


MALACHITE.  87 

GENUS  V.    EMERALD-MALACHITE. 

H=5.0 
G=3.2— 3.4. 

1.  RHQMBOHEDRAL  EMERALD-MALACHITE. 

Dioptase.    Emerald  Copper.    Phil.    C. 

Colour  emerald-green,  passing  into  blackish-green  and 
verdigris-green.  Streak  green.-  Transparent..,translu- 
cent.  Lustre  vitreous,  inclining  to  resinous.  Fracture 
conchoidal,  uneven.  Brittle.  Hardness  5.0.  Sp.gr.  3.27. 
Primary  form  an  obtuse  rhomboid  of  126°  17' and  53°  43'. 
It  frequently  occurs  in  what  appear  to  be  elongated  rhom- 
bic dodecahedrons. 

1.  Before  the  blow-pipe  on  charcoal  it  becomes  black  in  the 
exterior  of  flame,  and  red  in  the  interior,  without  melting.     It 
rs  soluble  in  borax,  and  imparts  to  it  a  green  colour.     In  mu- 
riatic acid  it  dissolves  without  effervescence. 

2.  It  consists  of 

25.57— Oxide  of  copper,      55.00 
28.57— Silex,  33.00 

0.00— Water,  12.00 

42.85— Carbonate  of  lime,  00.00 
Lowitz.  Vauquelin. 

GENUS  VI.    HABRONEME*-MALACHITE. 

H=3.5— 5.0. 
G=3.6— 4.3. 

1.  PRISMATIC  HABRONEME-MALACHITE. 

Prismatic  Olivenite  or  Phosphate  of  Copper.    Jam. 
Hydrous  Phosphate  of  Copper.    Phil. 

Colour  emerald-green  striate  with  blackish.  Streak 
green,  pale.  Translucent  on  the  edges.  Lustre  vitreous, 
inclining  to  adamantine.  Brittle.  Hardness  4.5.  Sp. 
gr.  4.  20.  Primary  form  is  considered  to  be  an  oblique 
rhombic  prism.  Cleavage  undetermined. 

1.  Before  the  blow-pipe  it  boils  and  melts  easily  into  a  small 
vesicular  metalloidal  globule. 

*  From  abros,  delicate,  and  nenia,  thread. 


88  MALACHITE. 

It  consists  of  Oxide  of  copper,  68.13—62.84 
Phosphoric  acid,  30.95—21.68 
Water,  00.00—15.45 

Klaproth.  Dunn. 

It  is  found  at  Bonn  and  Virneberg,  on  the  Rhine. 

2.  HEMI-PRISMATIC  HABRONEME-MALACHITE. 
Malachite.    Jam. 
Green  Carbonate  of  Copper.    Phil.    C. 

Colour  grass-green,  emerald-green,  verdigris-green,. 
Streak  green,  pale.  Translucent  on  the  edges.  Lustre 
vitreous,  often  pearly  and  adamantine.  Brittle.  Hard- 
ness 3.5— 4.0.  Sp.gri4.0.  Primary  form  right  rhombic 
prism.  Yields  readily  to  cleavage  parallel  to  the  planes 
P  and  M,  with  difficulty  to  T. 

Compound  varieties  are  usually  divided  into  compact  and 
fibrous  malachite ;  in  the  former  the  individuals  have  dis- 
appeared from  their  minuteness.  The  masses  are  often 
tuberose,  globular  and  botryoidal-  Structure  thin  colum- 
nar. Surfaces  often  drusy. 

1.  Before  theblow-pipe  it  decrepitates,  becomes  black  and  is? 
partly  infusible,  and  partly  converted  into  a  black  scoria.    It 
dissolves  easily  in  borax  to  which  it  imparts  a  green  colour,  and 
yields  a  globule  of  copper. 

It  consists  of         Copper,  58.00 

Oxygen,  12.50 

Carbonic  acid,       18.00 
Water,  11.50 

2.  It  occurs  in  the  same  repositories  as  the  other  ores  of  cop- 
per, especially  the  Prismatic  Azure  Malachite. 

It  is  .found  at  Southampton,  Mass.  ;  Perkiomen  lead  mine, 
Pa. ;  Cheshire,  Ct. 

Properties  of  the  following  minerals  are  not    sufficiently 
known  to  be  placed  in  the  system. 

1.  ATACAMITE, 
Prismatic  Alacamilt.    Jam. 
Muriate  of  Copper.    Phil.    C. 

Colour  olive,  leek,  grass,  emerald  arid  blackish-green. 


MALACHITE.  89 

Streak  apple-green.  Translucent.  Rather  brittle.  Hard- 
ness 3.0 — 3.5.  Sp.  gr.  4.43  Leonhard.  Cleavage  per- 
fect and  brilliant  parallel  to  P,  less  perfect  and  more  diffi- 
cult to  obtain  parallel  to  M  and  M'.  Primary  form  a  right 
rhombic  prism  of  100°  and  80°. 

1.  Exposed  to  the  flame  of  a  candle  it  tinges  it  blue  and 
green.  With  the  blow-pipe  it  is  'decomposed  with  the  devel- 
opement  of  muriatic  acid  vapours. 

It  consists  of  Oxide  of  copper,  73 
Muriatic  acid,  10 
Water,  16 

It  occurs  investing  some  of  the  lavas  of  Vesuvius. 

2.  BROCHANTITE. 

Brochantile.     Levy.    Ann.  of  Phil.  Oct.  1824.  p.  241. 

Colour  emerald-green.  Transparent,  Hardness  3.5— 
4.0. 

1.  It  is  considered  as  a  compound  of  sulphuric  acid  and 
oxide  of  copper,  containing  either  an  excess  of  base  or  silex  or 
alumina.  Occurs  in  Siberia. 

3.  EUCHROITE. 

Emerald  Euchroite.     Haidinger.    Eding.  Jour.  Science. 
Colour  bright  emerald-green.     Streak  pale  apple-green. 
Transparent... translucent.     Possesses  double  refraction. 
Brittle.     Hardness  3.5.— 4.0.     Sp.  gr.  3.38.     Fracture 
small  conchoidal. 

1.  Heated  in  a  matrass  it  loses  water  and  becomes  yellowish- 
green,  and  friable.  When  heated  to  a  certain  point  it  is  sudden- 
ly reduced  with  a  kind  of  deflagration, leaving  globules  of  malle- 
able copper.  It  occurs  at  Libethen,  in  Hungary,  in  quartzose 
mica  slate.  Its  proper  designation  is  Prismatic  Emerald-mala- 
chite. 

GREEN  IRON-EARTH.     Werner. 
. '  Malachite  f 

Colour  siskin-green,  passing  into  black  and  yellow. 
Streak  yellowish-gray.  Lustre  resinous.  Massive.  Frac* 
ture  even — uneven.  Surface  smooth  and  shining.  Com* 

8* 


90  MALACHITE. 

position  thin  columnar. '  Occurs  in  botryoidal,  reniform 
and  globular  forms,  and  sometimes  in  a  powder.  Brittle. 
Semi-hard  and  not  heavy. 

1.  Before  the  blow-pipe  it  becomes  black,  or  brown,  but 
does  not  melt.  Occurs  at  Schneeberg,  in  Saxony. 

5.  RADIATED  ACICULAR  OLIVENITE.    Jam. 
Oblique  Prismatic  Arseniate  of  Copper.    Phil. 

Colour  external  blueish-black,  passing  into  deep  black, 
verdigris-green  inclining  to  sky-blue.  Streak  verdigris- 
green.  Transparent  on  the  edges.  Lustre  pearly  on  the 
cleavage  planes.  Not  very  brittle.  Hardness  2.5 — 3.0. 
Sp.  gr.  4.19.  Primary  oblique  rhombic  prism  of  124° 
and  56°. 

1.  Before  the  blow-pipe  it  deflagrates  and  emits  arsenical 
vapors.  It  consists  of 

Oxide  of  copper,  54.00 

Arsenic  acid,        30.00 

Water,  16.00 

Found  only  in  Cornwall,  England. 

6.  SCORODITE. 

Malachite  f 

Martial  Arseniate  of  Copper.    Phil. 

Colour  principally  leek-green,  passing  into  white,  or 
also  into  olive-green  and  liver-brown.  Streak  white. 
Semi-transparent... translucent  on  theedges.  Lustre  vit- 
reous. Brittle.  Hardness  3.5 — 4.0.  Sp.  gr.  3.16. 

1.  Before  the  blow-pipe  it  emits  arsenical  vapours  and  melts 
into  a  reddish-brown  scoria,  which  acts  on  the  magnet.  It 
consists  of 

Arsenious  acid, ,  31.40 

Sulphuric  acid,  1.54 

Water,  18.00 

Protoxides  iron,  manganese, 

lime  and  magnesia,  47.80 

Occurs  in  the  Brazil  and  the  Cornish  mines. 


MICA.  91 

7.  VAUQUELINITE. 
Malachite  f 
ChromaU  of  Lead  and  Copper. 

Colour  blackish-green,  olive-green.  Streak  brownish- 
green.  Lustre  adamantine.  Faintly  translucent,  with  a 
fine  green  olive  tint,  opake.  Fracture  uneven.  Rather 
brittle.  Hardness  2. 5 — 3.0.  Sp.gr.  5.5 — 5.7  Leonhard. 
Occurs  in  minute  crystals,  irregularly  aggregated,  and 
constituting  a  thin  crust. 

Alone  before  the  blow-pipe  it  intumesces  a  little  and  then 
melts  into  a  grayish  globule,  giving  a  few  globules  of  lead, 
It  imparts  a  green  colour  to  borax. 
It  consists  of  Oxide  of  lead,         60.87 
Oxide  of  copper,     10.80 
Chromic  acid,         28.33 
It  occurs  at  Beresof,  in  Siberia,  and  also  in  Brazil. 

8.    VELVET-BLUE  COPPER.    Jam. 
Malachite  ? 

Colour  bright  smalt-blue.  Translucent.  Lustre  pear- 
ly. Occurs  in  short  capillary  crystals,  or  velvety  druses 
and  coatings.  Rare. 

Chemical  composition  unknown.  Occurs  at  Moldawa,  in 
the  Bannat  of  Temeswar,  with  other  ores  of  copper. 

ORDER  V.    MICA. 
GENUS  I.    EUCHLORE*-MICA. 

H.=l. 0—2.5. 
G.=2.5— 3.2. 

1.  RHOMBOHEDRAL  EUCHLORE-MICA. 

Prismatic  Copper-Mica.    Jam. 
Rhomboidal  Arseniale  of  Copper.    Phil. 

Colour  emerald-green,  grass-green.  Streak  emerald- 
green.. .apple-green.  Transparent... translucent.  Lustre 
pearly.  Sectile.  Hardness  2.0.  Sp.  gr.  2.54.  Pri- 
mary form  an  acute  rhomboid  of  110°  30'  and  69°  30'. 
Cleavage  perfect,  perpendicular  to  the  axis  of  the  prism. 

*  From  eiichloros,  bright,  lively  green. 


MICA. 


T  on  P'  or  P"  110° .30' 
P'onP"  69    12 

P  on  a  108    40 

P'or  P"  on  a   128    18 
a  on  ra  or  m'    124    42 

Phillips,  p.  317. 

1.  Before  the  blow-pipe  it  decrepitates,  and  passes  first  to 
the  state  of  a  spongy  scoria  ;  after  which  it  melts  into  a  black 
globule  of  a  slightly  vitreous  appearance.     With  borax  it  af- 
fords a  bead  of  copper. 

It  consists  of  Oxide  of  copper,  39.00 
Arsenic  acid,  43.00 
Water,  17.00  Vauquelin. 

2.  It  is  associated  with  other  ores  of  copper,  particularly 
those  of  the  order  malachite.     It  occurs  in  the  vicinity  of  the 
copper  mines  of  Redruth,  in  Cornwall. 

2.  PRISMATIC  EUCHLORE-MICA. 

Colour  pale  apple-green  and  verdigris-green,  inclining 
to  sky-blue.  Streak  apple-green,  paler.  Translucent  on 
the  edges.  Lustre  pearly.  Very  sectile.  Thin  lamina? 
flexible.  Hardness  1.0—1.5.  Sp.  gr.  3.09.  Occurs 
reniform  and  botryoidal.  Primary  form  an  oblique  rhom- 
bic prism. 

It  consists  of  oxide  of  zinc  and  copper.  Brooke.  Occurs 
in  the  Bannat  of  Temeswar,  and  in  Derbyshire,  Eng. 

3.  PYRAMIDAL  EUCHLORE-MICA. 

Pyramidal  Uranite.    Jam. 
Phosphate  of  Uranium.     Phil.    C. 

Colour  emerald-green,  grass-green,  and  sometimes  leek- 
green,  apple-green  or  siskin-green,  lemon  yellow,  gold- 


MICA.  93 

yellow.  Streak  corresponds  to  the  colour,  but  paler.  Lus- 
tre pearly.  Transparent. ..translucent  on  the  edges.  Sec- 
tile.  Hardness  2.0—2.5.  Sp.  gr.  3.11.  Fracture  not 
observable.  Primary  form  a  square  prism.  It  yields  to 
mechanical  division  with  remarkable  ease,  parallel  to  the 
plane  P.  It  is  found  crystalized  in  four,  six  and  eight- 
sided  tables.  Structure  perfectly  lamellar. 

1.  It  consists  of  Oxide  of  uranium,         60.00 

Phosphoric  acid,  16.00 

Oxide  of  copper,  9.00 

Water,  14.50 

Alone  before  the  blow-pipe  it  becomes  yellow,  and  loses  its 

transparency ;  upon  charcoal  it  intumesces  and  melts  into  a 

black  globule,  with  traces  of  crystalization  upon  the  surface  ; 

with  borax  it  yields  a  yellowish-green  bead  ;  in  nitric  acid  it 

forms  a  yellow  solution. 

2.  It  is  accompanied  with  the  ores  of  copper,  tin  and  urani- 
um.    Occurs  in  Cornwall,  and  other  mining  districts  in  Eu- 
rope. 

GENUS  II.     COBALT-MICA. 

::•>  :.•"'  H.=2.5 

G.=2.9— 3.1. 

1.  PRISMATIC  COBALT-MICA. 

Prismatic  red  Cobalt.    Jam. 
Arseniate  of  Cobalt.    Phil. 

Colour  grayish-white,  crimson-red  ;  peach  blossom-red 
it  sometimes  appears  by  transmitted  light.  Streak  corres- 
ponding to  the  colour,  though  a  little  paler.  Powder  of  the 
dry  mineral  possesses  a  deep  lavender-blue  tinge.  Trans- 
parent.,.translucent  on  the  edges.  Sectile  ;  thin  laminae 
flexible.  Hardness  1.5 — 2.0.  Sp.  gr.  2.94.  Primary 
form  a  right  oblique  angled  prism.  M  on  T  124°. 

1.  It  consists  of  Oxide  of  cobalt  34,  one  p. 
Arsenic  acid  58,  one  p. 

Water  18,  one  p. 

Before  the  blow- pipe  it  emits  abundant  fumes  of  arsenic* 
and  tinges  borax  blue. 


94  MICA. 

2.  It  occurs  principally  at  Schneeberg  and  Annaberg,  Sax- 
ony, in  primitive  rocks.  It  occurs  however,  in  rocks  of  all 
ages. 

GENUS  III.    IRON-MICA. 

H.=2.0 
G.=2.6— 2.7. 

1.  PRISMATIC  IRON-MICA. 

Prismatic  Blue-Iron.    Jam. 

Vivianile.     Phosphate  of  Iron.     Phil.     C. 

Colour  various  shades  of  blue  and  green.  Streak  blue- 
ish-white,  which  soon  changes  to  indigo-blue.  Powder 
when  dry,  liver-brown.  Transparent.. .translucent.  Sec- 
tile.  Thin  laminae  perfectly  flexible.  Lustre  pearly  on 
the  face  of  cleavage.  Hardness  1.5 — 2.0.  Sp.gr.  2.66. 
Primary  form  a  right  oblique  angled  prism.  Cleavage 
perfect,  only  parallel  to  the  plane  P.  Crystals  prismatic, 
aggregated  and  of  considerable  length  ;  it  sometimes  oc- 
curs in  reniform  and  globular  masses.  Composition  often 
impalpable  or  earthy. 

1.  It  decrepitates  before  the  blow-pipe,   but  melts,  if  first 
reduced  to  powder,  into  a  dark-brown  scoria,  which  moves  the 
magnetic  needle.     It  is  soluble  in  dilute  sulphuric  and  nitric 
acids.     Those  varieties  which  are  found  white  in  their  original 
repositories,  soon  assume  a  blue  tinge  on  exposure  to  light 
and  air.     It  consists  of  , 

Protoxide  of  iron,  47.50 
Phosphoric  acid,  32.00 
Water,  20.00 

2.  This  mineral  occurs  in  New- Jersey,  in  the  tertiary  for- 
mation,  particularly  at  Mullica  Hills,  Gloucester  co.     It  is 
found  there  in  cylindrical  masses,  which  are  composed  inter- 
nally of  groups  of  crystals,  radiating  from  different  centres. 
These  cylinders  are  about  two  inches  long  and  half  an  inch  in 
diameter,  externally  incrusted  with  a  brown  silicious  sand.    It 
is  likewise 'found  m  an  earthy  form  in  the  same  deposites. 


MICA.  95 

GENUS  IV.     GRAPHITE-MICA. 

H.-=l.  0—2.0. 
G.  =1.8— 2.1. 

1.  RHOMBOHEDRAL  GRAPHITE-MICA. 

Rhomboidal  Graphite.    Jam. 

Plumbago  Graphite.    Black  Lead.    Phil.    C. 

Colour  iron-black,  light  and  dark  steel-gray.  Streak 
black,  sbining.  Opake.  Lustre  metallic — highest  de- 
gree on  the  faces  of  cleavage.  Sectile.  Thin  laminae 
highly  flexible.  Hardness  1.0—2.0.  Sp.  gr.  2.08 
Haliy. 

Compound  varieties  occur  in  granular,  scaly  and  com- 
pact forms.  Fracture  of  the  granular  form  uneven.  Lus- 
tre glimmering. 

1.  Before  the  blow-pipe  it  is  combustible,  and  leaves  a  small 
residue  of  iron.  Infusible. 

Occurs  in  beds  in  slaty  or  primitive  rocks,  and  disseminat- 
ed in  the  form  of  scales.     It  consists  of 
Carbon,        96.00 

•  I.  •:•  Iron,  4.00     Saussure. 

One  of  the  most  remarkable  mines  of  this  mineral  is  that 
of  Borrowdale,  in  Cumberland,  Eng.  It  occurs  in  almost 
every  primitive  rock.  The  finest  localities  in  the  United 
States  are  in  the  vicinity  of  Lake-George,  N.  Y.  and  Sterling, 
Mass.  At  the  latter  locality  it  is  nearly  as  fine  as  that  of  Bor- 
rowdale. 

GENUS  V.     TALC-MICA. 

H.=1.0— 2.5. 
G.=2.7— 3.0. 

1.  PRISMATIC  TALC-MICA. 

Rhomboidal  Mica  (in  part.)    Jam. 

Talc.     Green  Earth.     Chlorite.    Phil.     C. 

Colour  various  shades  of  green,  varying  from  pale  to 
very  dark-green,  greenish  and  grayish-white.  Streajc 
corresponding  to  the  colour.  Translucent  in  very  thin 
scales.  Lustre  pearly.  Cleavage  monotonous.  Sec* 
tile  and  flexible.  Hardness  1.0 — 1.5.  Sp.  gr.  2.71. 


W  MICA. 

Compound  varieties  occur  in  stellular  groups,  and  in 
laminae  irregularly  aggregated.  Sometimes  slaty  and 
earthy.  The  more  common  forms  are  made  up  of  small 
scaly  shining  individuals,  strongly  coherent.  The  earthy 
or  impalpable  variety  is  termed  green  earth. 

1 .  Before  the  blow-pipe  some  varieties  lose  their  colour  and 
are  fused  with  difficulty  ;  others  are  changed  into  a  black  sco- 
ria, and  others  are  infusible.     It  is  composed  of 

Silex,  62.00 

Magnesia,  27.00 
Oxide  of  iron,  3.50 
Alumine,  1.50 

Water,  6.00 

2.  Included  in  the  description  of  Prismatic  Talc-mica  ore, 
those  varieties  are  known  under  the  name  of  Chlorite  and 
Talc  :  the  former  is  subdivided  into  foliated,  slaty  and  earthy 
chlorite,  which  are  of  a  dark-green  colour  :  the  latter  includes 
those  varieties  which  are  of  a  light  or  pale  green  colour,  and 
the  perfectly  white,  and  is  subdivided  into  common,  earthy  and 
indurated  talc. 

Scaly  talc,  or  Nacrite,  consists  of  particles  which  cohere 
but  slightly.  It  is  but  little  known,  and  is  considered  by  some 
mineralogists  as  a  distinct  species. 

3.  The  more  compact  kinds  of  Prismatic  Talc-mica  possess 
considerable  toughness  as  well  as  softness  ;  properties  which 
make  them  suitable  for  turning  and  forming  them  into  vessels 
of  various  kinds.     One  variety,  from  its  having  been  used  for 
coarse  pots,  has  received  the  name  of  Pot-stone.     Steatite  or 
soapstone  cannot  be  considered  as  more  than  a  mere  variety 

'  of  Prismatic  Talc-mica.  It  often  passes  into  serpentine,  as 
may  be  seen  by  inspecting  the  Middlefield  quarry  of  soap- 
stone  ;  indeed  the  quarry  itself  might  be  denominated  Steatitic 
Serpentine.  Soapstone  very  rarely  crystalizes  ;  the  only 
locality  in  the  United  States  is  that  of  Middlefield,  in  a  ledge 
of  serpentine,  in  the  south  part  of  the  town.  The  crystals  are 
yoipseudomorphous,  as  some  mineralogists  have  suggested. 

4.  Prismatic  Talc-mica  is  abundant.     It  forms  insulated 
beds  in  Talcose  Slate  on  one  side  and  Hornblende  on  the  oth- 
er.    Beds  of  this  mineral  may  be  traced  through  Vermont,  . 
some  of  which  may  be  seen  to  advantage  in  Newfane  ;  and 
across  Massachusetts  and  Connecticut,   nearly  in  the  same 
range.    The  vicinity  of  these  beds  furnish  nearly  the  same 


MICA.  97 

minerals  :  the  most  common  are  the  varieties  of  hornblende, 
drusy  quartz,  chrysoprase,  chalcedony,  epidote,  zoisite,  sea- 
polite,  &c. 

Scaly  talc  or  Nacrite  has  been  found  in  veins  of  lead.  It 
occurs  in  Middlefield,  about  one  mile  west  of  the  church. 
The  green  mica  of  Brunswick,  Me.  is  considered  as  Nacrite. 

2.  RHOMBOHEDRAL  TALC-MICA. 

Rhomboid  al- Mica  (ip  part.)     Jam. 
Mica.    Phil.     C. 

Colour  various  shades  of  gray,  green,  brown  and  black. 
Streak  white. ..gray.  Transparent  in  the  direction  of  the 
axis.  Lustre  pearly,  often  splendent  or  metallic.  Sec- 
tile.  Thin  laminae  flexible  and  elastic.  Hardness  2.0 — 
2.5.  Edges  of  the  laminse  sometimes  scratch  glass.  Sp. 
gr.  2.94.  Primary  form  an  oblique  rhombic  prism. 
Cleavage  eminent,  parallel  to  P.  M  on  M'  60°  00'.  P 
on  M'  98°  40'.  P  on  M  81°  20. 

It  occurs  in  the  form  of  six-sided  tables. 

Compound  varieties  rarely  globular  or  reniform  :  granu- 
lar form  common.  Sometimes  imperfectly  columnar. 

1.  Mica  before  the  blow-pipe  first  loses  its  transparency 
and  then  melts  into  a  scoria,  coloured  in  proportion  to  the  dark- 
ness of  the  specimen  employed.     Some  micas  are  infusible. 

It  consists  of    Alumina,  36.80 

Silica,  46.36 

Oxide  of  iron,  4.53 

Potash,  9.22 

Fluoric  acid  and  water,    1.81     Rose. 

2.  From  the  diversity  which  exists  in  the  optical  properties 
of  several  varieties  of  mica  from  different  localities,  and  like- 
wise from  the  different  results  obtained  by  chemical  analysis, 
it  is  plain,  that  two  or  more  species  still  exist  in  the  varieties 
comprehended  under  the  general  name  of  mica.     The  determi- 
nation of  these  species  can  be  made  only  by  a  correct  applica- 
tion of  the  principles  of  natural  history. 

3.  This  mineral  enters  largely  into  the  composition  of  most 
of  the  primitive  rock  formations,  and  is  an  essential  constitu- 
ent of  granite,  gneiss  and  mica  slate.     In  the  coarser  granite 
it  forms  large  plates  of  folia.     Beautiful  specimens  occur  in 

9 


98  MICA. 

the  Highlands,  in  the  state  of  N.  Y.  particularly  in  the  town 
of  Monroe. 

LEPIDOLITE. 

Colour  usually  peach-blossom  red,  sometimes  pale,  or 
even  passing  into  pale-green.  Sp.  gr.  2.83.  Composi- 
tion generally  granular,  though  sometimes  the  individuals 
are  large  and  cleavable. 

1.  Before  the  blow-pipe  upon  charcoal  it  fuses  very  easily 
into  a  transparent  globule. 

It  consists  of    Alumine,  33.61 

Silex,  49.06 

Oxide  of  manganese,     1.40 
Magnesia,  0.41 

Lithia,  3.60 

Potash,  4.18 

Fluoric  acid,  3.45 

Water,  4.18  , 

2.  The  large  cleavable  variety  occurs  in  Goshen,  Mass.   A 
fine,  but  less  cleavable  kind,  is  found  in  Brunswick,  Me. 

GENUS  VI.    PEARL-MICA. 

H.=3.5— 4.5. 
G. =3.0— 3.1. 

3.  RHOMBOIDAL  PEARL-MICA. 

Rhomboidal  Pearl- Mica.     Jam. 
Margarite.     Phil.    Fuchs. 

Colour  grayish-white,  passing  into  reddish.  Streak 
white.  Translucent.  Lustre  pearly.  Brittle.  Hard- 
ness 3.6 — 4.5.  Sp.  gr.  3.03.  Cleavage  perfect  in  one  di- 
rection. 

1.  It  is  composed  of  small  lamina?  which  intersect  each 
other  in  every  direction.  It  strongly  resembles  silvery  mica. 
It  consists,  according  to  M.  Du  Menil,  of 

Silex,  37.00 

Alumine,  40.50 

Oxide  of  iron,       4.50 

Lime,  8.96 

Soda,  1.24 


MICA.  99 

Water,  1.00 

Loss,  6.80 

2>  Rhombohedral  Pearl-Mica  has  been  found  in  a  bed  of 
primitive  rock,  mixed  with  Prismatic  Talc-mica,  at  Sterzing, 
in  the  Tyrol.  It  is  associated  with  rhombohedral  Fluor-hal- 
oide  and  axotomous  Iron-ore. 

The  following  minerals  belong  to  the  order  Mica,  but  are 
little  known,  and  are  not  designated  by  scientific  names. 

1.  CRONSTEDITE. 

Cronstedite.    Stcinmann*    Schweigger's  Journal. 
Cronsledite.    Phil. 

Colour  brownish-black.  Streak  dark  leek-green.  Opake. 
Thin  laminae  elastic.  Hardness  2.5.  *  Sp.  gr.  3.34. 
Steinmann. 

1.  Before  the  blow-pipe  it  froths  a  little  without  melting. 
With  borax  it  yields  a  black  opake  globule.  Reduced  to  pow- 
der it  gelatinizes  with  muriatic  acid. 

It  consists  of        Silex,  22.45 

Oxide  of  iron,  58.53 

Oxide  of  manganese,    2.88 
Magnesia,  5.07 

Water,  10.70 

It  occurs  at  Przibram,  in  Bohemia,  associated  with  silver 
ores. 

2.  HYDRATE  OF  MAGNESIA. 

Mica  ? 

Native  Hydrate  of  Magnesia.    Brewster.    Trans.  Roy.  Soc.  Ed.  v.  ix. 
Hydrate  of  Magnesia.    Phil.     C. 

Colour  white,  inclining  to  green.  Streak  white.  Trans- 
lucent on  the  edges.  Sectile.  Lustre  pearly.  Thin 
laminae  flexible.  Hardness  1.0 — 1.5.  Sp.  gr.  2.35. 
Massive,  rarely  crystalized. 

1.  Before  the  blow-pipe  it  loses  its  water  and  becomes  fria- 
ble.    In  acids  it  dissolves  without  effervescence. 
It  consists  of         Magnesia,        70 
Water,  30 

It  occurs  in  thin  veins  in  serpentine,  at  Hoboken,  N.  J.      , 


100  SPAR. 

3.  PYROSMALITE. 

Pyrosmalite.    Jam.    Phil.    C. 

Colour  pale  liver-brown,  passing  into  gray  and  green. 
Streak  paler  than  the  colour.  Translucent... opake.  Lus- 
tre pearly.  Brittle.  Hardness  4.0 — 4.5.  Sp.  gr.  3.07. 
Hausmann. 

1.  Before  the  blow-pipe  it  becomes  reddish-brown,    and 
gives  off  the  vapours  of  muriatic  acid.  In  a  strong  fire  it  melts- 
into  a  globule,  which  is  attractable  by  the  magnet. 

It  consists  of 

Silex,  35.85 

Protoxide  of  iron,  21.81 

Protoxide  of  manganese,  21.14 

Muriate  of  iron  with  excess  of  base,  14.09 

Lime,  1.21 

Water,  5.89 

2.  It  occurs  in  the  iron  mines  of  Nordmark,  in  Wermerland 
in  Sweden. 

ORDER  VI.    SPAR. 
GENUS  I.    SCHILLER-SPAR. 

H.=3.5— 6.0. 
G.=2.6— 3.4. 

1..  DIATOMOUS*  SCHILLER-SPAR. 

Common  Schiller-Spar.    Jam. 
Schiller-Spar  (in  part.)     Phil.     C. 
Diallage  (in  part.) 

Colour  olive-green  and  blackish-green,  inclining  to 
pinchbeck  brown  upon  the  perfect  faces  of  cleavage. 
Streak  grayish-white,  inclining  a  little  to  yellow.  Trans- 
lucent on  the  edges.  Lustre  pearly-metallic  upon  the 
cleavage  planes.  Rather  sectile.  Hardness  3.5 — 4.0. 
Sp.  gr.  2.69.  Cleavage  perfect  in  one  direction,  and  tra- 
ces of  cleavage  in  another,  producing  faces  of  crystaliza- 

*  From  did,  through,  and  tcmno,  I  cut :— easily  cleavable  in  one 
direction  through  the  crystals. 


SPAR.  101 

tion  which  incline  to  each  other  at  angles  of  135°.  Com- 
position usually  lamellar,  but  sometimes  passing  into  gran- 
ular. 

1.  Before  the  blow-pipe  it  becomes  hard,  forming  a  porce- 
lain-like mass.     It  consists  of  Silex,  62 

Magnesia,        10 
Alumina,  13 

Oxide  of  iron,   13 

2.  The  present  species  is  found  imbedded  in  serpentine.   It 
is  difficult  to  cite  localities  of  this  mineral  with  accuracy,   as 
it  is  easy  to  confound  or  mistake  for  it  the  following  species  : 
In  Europe,  the  Baste,   in  the  forest  of   Harzeburg,    in  the 
Hartz,  is  the  only  locality  which  is  distinctly  indicated.     A 
mineral  agreeing  very  nearly  with  the  description,    occurs  in 
Blandford,  Mass,  on  the  Westfield  road,  in  a  block  of  serpen- 
tine. 

2.  HEME-PRISMATIC  SCHILLER-SPAR, 

Bronzite.     Schiller-Spar  (in  ptfrt.l)  •  V-hjl. '.  C.         \  /  » ' 

Colour  dirty  shades  of  leek-green  and  blacjkisb-grfefiqtf  5 :  ;  . 
brown  liver-brown,  hair-brown  and  clbve-"brown  ;" green-' 
ish'and  ash-gray.     Streak  corresponds  to  the  colour,  but'  a 
little  paler.     Lustre  metallic-pearly  on  the  faces  of  cleav- 
age, and  vitreous  on  a  recent  fracture.     When  the  colour 
is  pinchbeck-brown  the  lustre  is  heightened,  or  becomes 
metallic.     Sectile.     Hardness  4.0 — 5.0.     Sp.  gr.  3.25. 

1.  Before  the  blow-pipe  it  loses  its  water,  becomes  lighter 
coloured,  but  is  infusible.     It  consists  of 

Silex,  60.00 

Magnesia,  27.50 

Oxide  of  iron,  10.50 

Water,  0.50 

2.  It  occurs  in  beds  in  serpentine,  often  mixed  with  hemi- 
prismatic  Augite-spar. 

It  is  found  in  Warwick,  near  Amity  church,  associated  with 
green  spinelle  and  brown  hornblende,  in  carbonate  of  lime.  It 
has  become  scarce. 

9* 


102  SPAR. 

3.  PRISM ATOIDAL  SCHILLER-SPAR. 

Hypersthene,  or  Labrador  Schiller-Spar.    Jam. 
Hypersthene.     Phil.     C. 

Colour  dark-brown  or  greenish-black  :  Several  varie- 
ties almost  copper-red  on  the  faces  of  cleavage.  Streak 
greenish-gray.  Thin  laminae  translucent.  Lustre  highly 
metallic-pearly  upon  the  face  of  cleavage.  Brittle.  Hard- 
ness 6.0.  Sp.  gr.  3.38.  Fracture  uneven.  Cleavage 
parallel  to  the  sides,  of  a  four-sided  prism  of  87°  and  93°. 
More  perfect,  parallel  to  the  short  diagonal,  and  traces 
parallel  to  the  long  diagonal  of  the  prism. 

1.  Before  the  blow-pipe  it  is  but  little  changed,  but  melts 
on  charcoal  into  a  greenish-gray  opake  globule,  easily  soluble 
in  borax. 

2.  According  to  the  late  analysis  of  this  mineral  by  Prof. 
TfiompsQni  4%  "elements  of  the  Isle  of  Skye-Hypersthene  and 
the  Paulite  of  Labrador  are  as  follows  :  : 

Mt£    :£  •'VPauMle.  Isle  of  Skye  Hypersthene. 

;5ilex,             —  46.11  51.34 

Magnesia,              25.87  11.09 

Peroxide  of  iron,    14.11  33.92 

Lime,                      5.29  1.83 

Alumine,                  4.06  0.00 

Water,                    0.48  0.50 

Mn.  Lyceum  JV.  Y.  jflpril,   1828, 

Notwithstanding  there  is  a  difference  in  the  chemical  consti- 
tution of  the  Paulite  and  the  Isle  of  Skye-Hypersthene,  yet 
they  appear  to  constitute  but  one  species  ;  both  seem  to  be  es- 
sentially composed  of  Silex,  Magnesia  and  Iron  :  the  Paulite 
consisting  of  3  atoms  of  bisilicate  of  magnesia  and  1  of  iron, 
while  the  Hypersthene  contains  2  atoms  of  bisilicate  of  mag- 
nesia and  3  atoms  bisilicate  of  iron.  The  composition  of  Hy- 
persthene in  general  is  denoted  by  the  formula— x  M  n  S  2-j-y 
FS.  x  &  y — denoting  the  unknown  number  of  atoms  of  the 
two  bisilicates.* 

*  Fr.  Kohler  infers  from  his  late  examination  of  Metalloidal  Diaf- 
loge,  Bronzite  and  Hypersthene,  that  they  are  mineralogically  and 
chemically  identical  with  Augite  or  Pyroxene.  Poggendorff,  Ann.xii. 
p.  101—quoted  in  vol.  20  of  the  rfmtr.  Jour.  Science,  p.  168. 


SPAR.  103 

4.  PRISMATIC  SCHILLER-SPAR. 
Anihophyllite.    Jam.     Phil.     C. 

Colour  between  yellowish- gray,  clove-brown  and  green- 
ish-black. Streak  white,  translucent,  sometimes  only  on 
the  edges.  Lustre  pearly,  inclining  to  metallic,  particu- 
larly on  the  face  of  cleavage.  Brittle.  Hardness  5.0 — 
5.5.  Sp.  gr.  3.12.  Cleavage  parallel  to  the  sides  of  a 
four-sided  prism  and  both  diagonals,  but  more  distinct  in 
the  direction  of  the  long  diagonal.  Inclination  of  the  faces 
about  1240.30'. 

Compound  varieties. — Composition  columnar,  straight, 
divergent  and  rather  broad. 

1.  Before  the  blow-pipe  alone  it  is  not  altered.     Borax  dis- 
olves  it  with  difficulty,  and  yields  a  glass  coloured  with  iron. 

It  consists  of  Silex,  56.00 

Alumine,  13.30 

Magnesia,  14.00 

Oxide  of  iron,  6.00 
Oxide  of  manganese,  3.00 

Lime,  3.00 

Water,  1.43     John. 

2.  Anthophyllite  occurs  in  Chesterfield,  Chester  and  Bland- 
ford,  Mass.     It  is  generally  associated  with  pyroxene,  garnet, 
and  staurolide,  imbedded  in  mica-slate. 

The  mineral  found  near  the  city  of  New- York,  well  known 
to  mineralogists  as  radiated  asbestus  or  actynolite,,  and  sup- 
posed by  some  to  be  anihophyllite,  has  been  determined  by 
Prof.  Thompson  to  be  a  new  mineral :  It  consists  of 

Silex,  54.98 

Magnesia,  13.37 

Protoxide  of  iron,  8.84 

Do.         manganese,  1.20 

Potash,  6.80 

Alumine,  1.56 

Water,  11.44 

The  formula  given  for  this  analysis  is— 5  M  S3-f2/S3-f~k 
S3+9£Aq.  It  maybe  denominated  hydrous  Anthophyllite, 
Thompson. 


104  SPAR. 

GENUS  II.    DISTHENE-SPAR. 

H.  =5.0—7.0 
G.  =6.0—3.7 

1.  PRISMATIC  DISTHENE-SPAR. 

Prismatic  Kyanite.    Jam. 
Kyanite.     Cyanite.    Phil.    C. 

Colour  some  shade  of  blue,  as  sky-blue,  passing  into 
white,  or  inclining  into  green  or  gray  :  intensity  of  col- 
our not  uniform,  but  frequently  appearing  deep  blue  in 
spots,  passing  off  into  pale  blue  or  white.  Streak  white. 
Transparent... translucent.  Lustre  pearly  on  the  cleavage 
planes.  Rather  brittle.  Hardness  5.0 — 7.0  :  the  high- 
est degree  appears  on  the  solid  angles  and  edges.  Sp.  gr. 
3.67.  Cleavage  parallel  to  all  the  planes  of  a  doubly 
oblique  prism  :  difficult,  parallel  to  the  terminal  planes  : 
perfect  in  the  direction  M  and  T. 


.  .                    MonT 

106° 

15' 

/     -m    \              P  on  M 

100 

50 

V       -T      \            ..  on  T 

93 

15 

\.               3 

i 

97 

48 

;*  —  4r^ 

'.'...'.  k 

83 

38 

T 

Mon   i 

145 

1(> 

i 

M 

T  on   i 

140 

55 

k 

/ 

122 
>;,;/    7i 

20 
r.w 

Phil.  Mineralogy}  p.  82. 
'    1.  Before  the  blow-pipe  it  is  infusible,  but  dissolves  with 
difficulty  in  borax.     It  consists  of 
Alumina,  55.5     Silica,  43.0     Oxide  of  iron,  0.5     Klaproth. 

Prismatic  Disthene-spar  always  occurs  in  primitive  rocks, 
more  particularly  in  mica  slate  ;  it  is  most  commonly  in  long 
crystaline  masses,  the  individuals  of  which  are  applied  to  each 
other  by  thin  broad  planes. 

2.  It  occurs  at  Chesterfield,  Worthington,  Middlefield  and 
Chester,  Mass.  At  the  latter  place,  small  dark  coloured  he- 
mitrope  crystals  occur  in  a  black  fine  grained  mica  slate.  The 
variety,  Rhcetizite,  is  composed  of  aggregated  fibres,  generally 
interlaced,  and  of  a  reddish  or  grayish-white  colour.  It  has 
the  s"ame  geological  relation  as  the  species.  It  occurs  in 
Blandford  and  Hussel,  Mass. 


SPAR.  105 

GENUS  III.    TRIPHANE-SPAR. 

H.=6.0— 7.0. 
G.=2.8— 3.1. 

1.  PRISMATIC  TRIPHANE-SPAR. 

Prismatic  Spodumene.    Jam. 
Spodumene.    Phil.     C. 

Colour  various  shades  of  grayish-green,  passing  into 
greenish-white,  likewise  reddish-white  and  brown.  Frac- 
ture uneven.  Lustre  pearly.  Streak  white.  Translucent 
on  the  edges.  Moderately  brittle.  Hardness  6.5 — 7.0. 
Sp.gr.  3.17.  It  yields  to  mechanical  division  parallel  to  the 
sides  of  a  rhombic  prism  of  about  100°  and  80°,  likewise 
to  the  shorter  diagonal.  Structure  perfectly  lamellar. 

1.  Alone  before  the  blow-pipe  on  charcoal,  it  intumesces  and 
fuses  into  colourless  and  almost  transparent  beads.     It  intu- 
mesces but  does  not  fuse  so  readily  with  borax.     With  salt  of 
phosphorus  it  intumesces,  and  leaves  a  skeleton  of  silica. 

It  consists  of  Silex,  66.04 

Alumine,          25.03 

Lithia,  8.85 

Oxide  of  iron,    1.45 

Hence  it  is  composed  of  1  atom  of  trisilicate  of  lithia-|-3  atoms 
of  bisilicate  alumina. 

2.  It  occurs  in  Goshen,  Mass,  and  Saratoga,   N.  Y.  in 
coarse  grained  granite. 

2.  AXOTOMOUS  TRIPHANE-SPAR. 

Prismatic  Prenite.    Jam. 
Prehnite.    Phil.     C. 

Colour  various  shades  of  green,  as  leek-green,  apple- 
green,  likewise  passing  into  white  and  gray.  Streak 
white.  Lustre  vitreous.  Semi-transparent. ..translucent. 
Brittle.  Hardness  6.0—7.0.  Sp.  gr.  2.92. 

Compound  varieties  occur  mostly  in  two  forms— -fibrous 
and  foliated.  It  assumes  reniform,  botryoidal,  stalactitic 
and  globular  shapes.  Surface  always  drusy  or  rough. 


106  SPAR. 

1.  Before  the  blow-pipe  it  becomes  a  white  frothy  scoria, 
and  then  melts  into  a  compact  globule,  which  becomes  trans- 
parent with  borax.    It  dissolves  slowly  in  dilute  Muriatic  acid. 

It  consists  of      *       Silex,  43.83 

Alumina,         30.33 

Lime,  18.53 

Oxide  of  iron,    5.66 

Water,  1.83    KlaprotJi. 

It  agrees  with  the  composition  of  1  atom  bisilicate  of  lime-f 
2  atoms  silicate  of  alumina. 

2.  This  mineral  was  first  brought  from  the  Cape  of  Good 
Hope,  by  Colonel  Prehn.     Since  that  time  it  has  been  discov- 
ered in  many  countries  :  it  is  commonly  found  in  trap  rocks, 
and  particularly  greenstone,  but  rarely  in  primitive.     It  is 
found  in  New-Jersey,  Connecticut,  Vermont  and  Massachu- 
setts, wherever  trap  rocks  occur.    At  Bellows  Falls,  in  VU 
it  occurs  in  a  coarse  mica  slate, 

GENUS  IV.    DISTOME-SPAR. 

H.=&0— 5.5. 
G.=a2.9— 3.0. 

1.  PRISMATIC  DISTOME-SPAK. 

Prismatic  Datolite.    Jam. 
Borate  of  Lime.    Phil.    C. 

Colour  white,  inclining  to  green,  yellow  or  gray.  Some- 
times dirty  olive-green  or  of  a  honey-yellow  tinge.  Streak 
white.  Translucent  in  various  degrees.  Lustre  vitreous, 
inclining  to  resinous.  Brittle.  Hardness  5.0 — 5.5.  Sp. 
gr.  2.98.  Fracture  imperfectly  conchoidal.  Primary 
form  a  right  rhombic  prism  of  103°  40'  and  76°  20'.  P 
on  M  or  M'  90°  00'.  M  on  M'  103°  40'. 

Compound  varieties  have  a  granular  structure.  That 
variety  which  consists  of  mammillary  concretions,  formed 
of  concentric  layers  on  a  splintery  fibrous  structure,  has  re- 
ceived the  name  of  Botryolite. 

1.  Before  the  blow-pipe  it  loses  its  transparency,  intumes- 
ces  and  melts  into  a  glossy  globule.  In  the  flame  of  a  candle 
it  becomes  friable.  It  is  easily  soluble  in  nitric  acid,  forming 


SPAR.  107 

a  siliceous  gelatine.    If  the  powder  be  moistened  with  a  drop 
of  muriatic  acid  and  dried  on  a  slip  of  paper,  and  then  wet 
with  alcohol  and  burnt,  the  flame  towards  the  end  of  combus- 
tion will  be  tinged  green. 
This  mineral  consists  of    Silex,  36.50 

Lime,  35.00 

Boracic  acid,   24.00 
Water,  4.00    Klaproth. 

The  chemical  composition  is  1  atom  of  bi-borate  of  lime+ 
1  atom  of  tri-silicate  of  lime-fl  atom  of  water.  Berzelius. 

2.  It  occurs  in  primitive  as  well  as  trap  rocks,  accompanied 
with  octahedral  Fluor-haloide,  rhombohedral  Quartz  and  axo- 
tomous  Triphane^spar. 

It  occurs  at  Patterson,  N.  J, 

GENUS  V,    KOUPHONE*-SPAR. 

H.  =3.5—6.0 
G.  =2.0—2.5 

1.  TRAPEZOIDAL  KOUPHONE-SPAR. 

Dodeeahedral  Zeolite  or  Leucite.  Jam.     Leucite.  Phil.   C. 

Colour  reddish,  yellowish  or  grayish-white  ;  ash  or 
smoke-gray.  Streak  white.  Semi-transparent... translu- 
cent^ Lustre  vitreous.  Brittle.  Hardness  5.5.  Sp.  gr. 
2.48.  It  yields  to  cleavage,  though  imperfectly,  parallel 
to  the  planes  of  the  cube,  which  is  considered  as  the  pri- 
mary form.  Generally  occurs  in  the  form  of  a  trapezoe- 
dron  as  represented  in  the  figure. 


c  on  c        =131°  48'  16' 

C 

=146    26    33 

Hauy. 

See  Phil.  Mineralogy,  p.lQS. 


j  on  c"   ) 
or         V: 
j'  on  c'"  ) 


This  mineral  exhibits  double  refraction,  which  phenom- 
enon is  an  exception  to  the  law  which  has  been  stated,  viz. 

*  From  Kouphof,  light. 


108  SPAR. 

that  the  platonic  solids  do  not  possess  the  doubly  refractive 
power. 

1.  Before  the  blow-pipe  it  is  infusible,  but  with  borax  or 
lime  it  fuses  with  difficulty  into  a  clear  globule.     Reduced  to 
powder  it  changes  the  colour  of  tincture  of  violets  into  green. 
It  consists  of  Silex,  54.00 

Alumine,  24.00 

Potash,  22.00 

Specimen  from  Jttbano  by  Klaproth. 

According  to  the  analysis,  Leucite  is  a  bi-silicate  of  alumine 
and  potash. 

2.  This  species  occurs  chiefly  in  imbedded  crystals  and 
grains  in  lava.    It  occurs  at  Vesuvius  and  Albano. 

2.  DODECAHEDRAL  KOUPHONE-SPAR. 
Sodalite,    Jam.    Phil.    C. 

Colour  green,  greenish-white,  passing  into  grayish  and 
snow-white.  Streak  white.  Lustre  vitreous.  Transpar- 
ent. Brittle.  Hardness  5.5—6.0.  Sp.  gr.  2.29.  It 
yields  to  mechanical  division  parallel  to  the  planes  of  a 
rhombic  dodecahedron  as  well  as  the  cube.  P  on  P'  or  P 
on  P"  or  P'  on  P"  120°  00'. 

1.  Alone  before  the  blow-pipe  on  charcoal  it  suffers  no 
change,  except  that  its  edges  become  rounded  :  with  borax  it 
affords  with  difficulty  a  transparent  glass.  It  consists  of 


Silex, 

38.52 

Alumine, 

27.48 

Soda  and  a  little  ? 
potash,           $ 

23.50 

Muriatic  acid, 

3.00 

Lime, 

2.10 

Oxide  of  iron, 

1.00 

Volatile  substances,  2.10     Thompson. 

The  composition,  according  to  this  analysis,  is  1  atom  of 
silicate  of  soda  -f  2  atoms  of  silicate  of  alumina. 

2.  The  dodecahedral  Kou phone- spar  is  found  in  West- 
Greenland,  in  a  bed  of  mica  slate,  accompanied  with  feldspar, 
zircon  and  pyroxene.4 


SPAR.  109 

3.  HEXAHEDRAL  KOUPHONE-SPAR. 

Hexahedral  Zeolite  or  Jlnalcime.    Jam.  Phil.  C. 
Colour  white  prevalent,  passing  into  gray,  reddish-white 
and  flesh-red.     Transparent... translucent.     Lustre  vitre- 
ous.    Brittle.     Hardness  5.5.     Sp.  gr.  2.06.     Cleavage 
apparently  parallel  to  the  faces  of  the  cube. 
1.  2- 


Fig.  1 .  The  primary  cube.  Fig.  2.  The  same  of  which  each  solid  angle  is 
truncated  or  replaced  by  three  planes.  Fig.  3.  The  secondary  plane  of  fig. 
2,  complete.  The  trapezoidal  planes  incline  on  the  primary  1449  44'  and  on 
each  other  at  angles  of  146°  26'. 

The  compound  varieties  are  massive,  with  a  granular 
composition. 

1.  Upon  charcoal  it  melts  without  ebulition  into  a  clear  glass. 
It  gelatinizes  in  Muriatic  acid.     It  consists  of 

Silex,        58. 

Alumina,   18. 

Soda,         10. 

Lime,          2. 

Water,         8.50 

It  corresponds  to  1  atom  bisilicate  of  soda+3  atoms  of  bisili- 
cate  of  alumina+3  atoms  water.  This  mineral  usually  occurs 
in  trap  rocks,  rarely  in  primitive. 

2.  It  is  found  in  Chester,  in  the  form  of  implated  globules, 
or  imperfect  crystals  on  mica  slate,   which  exhibit  half  the 
number  effaces  of  the  trapezoidron. 

4.  PARATOMOUS  KOUPHONE-SPAR. 

Pyramidal  Zeolite  or  Crow  Stone.    Jam. 
Harmotome.    Phil.     C. 

Prevailing  colour  white,  passing  into  gray,  yellow,  red 
and  brown.  Streak  white.  Semi-transparent... translu- 
cent. Lustre  vitreous,  passing  into  pearly.  Brittle. 
Hardness  4.5.  Sp,  gr.  £.39.  It  yields  to  mechanical 

10 


110  SPAR. 

division  parallel  to  the  planes  and  both  diagonals  of  a  right 
rectangular  prism. 

1.  Before  the  blow-pipe  it  fuses  easily  without  intumescence 
into  a  diaphonous  glass,  with  borax  into  a  colourless  glass. 

It  consists  of  Silex,          49. 

Alumirie,  16. 
Baryta,  18. 
Water,  15. 

It  is  represented  as  consisting  of  1  atom  of  quadricilicate  of 
baryta+4  atoms  bisilicate  of  alumina+7  atoms  of  water. 

2.  It  occurs  in  cruciform  crystals  in  metaliferous  veins,  as- 
sociated with  baryta  and  calc  spar,  as  at  Andreasberg,  in  the 
Hartz.    Rare. 

5.  RHOMBOHEDRAL  KOUPHONE-SPAR. 

Rhombohedral  Zeolite  or  Chabasile.    Jam. 
Chabasie.    Phil.     C. 

Colour  white,  grayish  and  yellowish-white,  the  latter 
confined  to  the  surfaces.  Streak  white.  Semi-transparent 
...translucent.  Lustre  vitreous.  Brittle.  Hardness  4.0 — 
4.5.  Sp.  gr.  2.10.  Cleavage  pretty  distinct,  parallel  to 
the  planes  of  an  obtuse  rhomboid  of  94°  46'  and  86°  14'. 

1.  Before  the  blow-pipe  it  melts  into  a  white  frothy  mass. 
It  is  not  acted  upon  by  acids.     It  consists  of  1  atom  of  trisili- 
cate  of  lime+3  atoms  of  bisilicate  of  alumine+6  atoms  of  wa- 
ter. 

2.  Chabasie  is  confined  mostly  to  trap  rocks,  in  which  it 
occurs  in  cavities  or  geodes.     It  usually  appears  under  the 
primary  form. 

It  occurs  at  Chester,  in  Mica  Slate,  accompanied  with  Stil- 
bite  and  Heulandite,  and  hexahedral  prisms  of  carbonate  of 
lime.  It  is  scarce  and  nearly  exhausted. 

The  variety,  termed  Mesoline,  occurs  in  whitish  crystaline 
coats,  lining  the  cavities  of  an  amygdaloidal  rock  in  Faroe. 

6.  DIATOMOUS  KOUPHONE-SPAR. 

Di-prismalic  Zeolite  or  Laumonile.    Jam. 
Laumonite.    Phil.     C. 

Colour  white,  passing  into  reddish,  yellowish  or  gray- 
ish tints.  Streak  white.  Lustre  when  recently  fractured 


SPAR. 


Ill 


vitreous,  inclining  to  pearly.     Translucent.     Not  very 
brittle.     Hardness  Sp.  gr.  2.3.     It  yields  to  me- 

chanical divisions  parallel  to  the  planes  and  both  the  di- 
agonals of  an  oblique  rhombic  prism. 


MonM'-  113°  30' 
PonMorM'  86  15 
M  or  Mono  104  20 

Phil.  Mineralogy,  p.  46. 


1.  Before  the  blow-pipe  it  behaves  like  the  preceding  spe- 
cies. It  gelatinizes  in  acids  and  becomes  electric  by  friction. 
When  exposed  to  the  air  it  disintegrates  and  falls  to  a  white 
mealy  powder.  Diatomous  Kouphone-spar  yields  by  analysis, 

Silex,        48.30 
'  Alumine,  22.70 
Lime,        12.10 
Water,      16.00     Vogel. 

This  mineral  is  composed  of  1  atom  of  bisilicate  of  lime-f 
4  atoms  of  bisilicate  of  alumina+6  atoms  of  water. 

2.  It  is  usually  found  in  trap  rocks,  accompanied  by  others 
of  the  same  genus.     It  thus  occurs  in  the  trap  of  Connecticut, 
Maine  and  Nova-Scotia.    See  Min.  and  Geol.  of  Nova-Scotia, 
by  Messrs  C.  T.  Jackson  and  Francis  Alger. 

7.  PRISMATIC  KOUPHONE-SPAR. 

Prismatic  Zeolite  or  Mesotype.    Jam. 
Mesotype.     Phil.     C. 

Colour  generally  grayish-white.  Streak  white.  Trans- 
parent...translucent.  Lustre  vitreous.  Brittle.  Hard- 
ness 5.0 — 5.5.  Sp.  gr.  2.24.  It  cleaves  parallel  only 
to  the  side  of  a  prism  of  91°  20'  and  88°  40'. 

The  compound  varieties  are  often  fibrous,  either  .parallel 
or  radiated  ;  it  appears  too  in  an  earthy  form,  which  are 
soft  and  friable  masses  and  of  a  rough  meagre  feel :  it  is 
known  as  the  Mealy  Zeolite. 


SPAR. 


1.  Before  the  blow-pipe  on  charcoal  it  loses  its  transparency 
and  melts  into  a  glassy  globule. 

Three  varieties  seem  to  be  comprehended  under  this  spe- 
cies— the  Scokzite,  Mesolite  or  Needkstone,  and  Natrolite. 
The  compositions  of  each  is  as  follows  : 

Scolezite.          Mesolite.          Natrolite. 

Silica,  46.75  47.46  47.21 

Alumina,  24.82  25.35  25.60 

Soda,  0.39  4.87  16.12 

Lime,  14.20  10.04  0.00 

Water,  13.64  12.41  8.88 

Oxide  of  iron,        0.00  0.00  1.35 

The  atomic  combination  seems  to  be  1  atom  of  tri-silicate  of 

soda+3  atoms  of  silicate  of  alumina+2  atoms  of  water. 
The  general  repository  of  the  prismatic  as  well  as  other 

Kouphone  spars,  is  in  the  cavities  6f  trap  rocks,  accompanied 

generally  with  calcareous  spar. 

8.  PRISMATOIDAL  KOUPHONE-SPAR. 

Prismatoidal  Zeolite  or  Stilbite.    Jam. 
Slilbite.    Phil.    C. 

Prevailing  colour  white,  reddish- white  and  flesh-red. 
Streak  white.  Translucent.  Lustre  vitreous,  inclining 
to  pearly  on  the  faces  of  cleavage.  Brittle.  Hardness 
3.5 — 4.0.  Sp.  gr.  2.16.  Primary  form  a  right  prism 
with  rectangular  bases.  It  yields  to  cleavage  parallel  to 
the  planes  T  and  M. 


M  on  T  90°  00' 

P  on  M  or  T  90  00 
Monk  120  30 
a  on  a  118  50 

Mond         133   38? 
Phil.  Min.  p.  37. 


In  the  compound  varieties  the  crystals  are  often  aggre- 
gated in  the  form  of  sheafs,  or  collected  into  stellular 
groups,  or  inflated  globular  masses.  Fracture  often  pre- 
sents broad  folia,  of  a  beautiful  pearly  lustre. 


SPAR.  ,  US 

1.  Before  the  blow-pipe  it  exfoliates  and  melts  into  vesicu- 
lar globules.     It  does  not  gelatinize  with  acids. 

It  consists  of  Alumine,     16.10 

Silex,  58.00 
Lime,  .  9.20 
Water,'  16.40  Hisinger. 

Atomic  constitution  is  1  atom.tri- silicate  of  lime+3  atoms  of 
tri-silicate  of  alumina+6  atoms  water. 

2.  It  occurs  at  Chester,  Mass,  -in  Mica  Slate.     In  Nova- 
Scotia  in  trap.     At  the  latter  place  it  is  abundant. 

9.HEMI-  PRISMATIC  KOUPHONE-SPAR. 
Prismatoidal  Zeolite  or  Stilbite.    Jam. 
Heulandile.    Phil.     C. 

Colour  various  shades  of  white  passing  into  flesh-red, 
gray  and  brown.  Streak  white.  Transparent... translu- 
cent on  the  edges.  Lustre  strongly  pearly  on  the  plane  P. 
Brittle.  Hardness  3.5 — 4.0.  Sp.  gr.  2.20.  It  yields 
to  mechanical  division  parallel  only  to  the  plane  P  of  a 
right  oblique  angled  prism,  which  is  the  primary  form. 
P  on  M  or  T  90°  00'.  M  on  T  130°  00'.  Brooke. 

Compound  varieties  are  usually  in  globular  and  stellu- 
lar forms,  strongly  resembling  those  of  stilbite. 

1.  Before  the  blow-pipe  it  gives  the  same  results  as  the  for- 
mer species.     It  consists  of 

Alumina,  10.00  7.19 

Silica,  45.00  59.90 

Carb.  lime,  16.00  0.00 

Lime,  11.00  16.87 

Water,  12.00  13.43 

Oxide  of  iron,  4.00  1Q.OO 

„     manganese,  0.50  0.00 

Laugier.         Walmstedt. 

2.  It  occurs  in  the  same  natural  repositories  as  the  other 
species  of  Kouphone  Spars.     It  occurs  in  Chester,  in  mica 
elate. 

10.  PYRAMIDAL  KOUPHONE-SPAR. 

Axifrangible  Zeolite  or  Apophyllite  (in  part.)    Jam. 
Jtpophyllite.    Phil.    C.  Mesotype  epointee.    Haiiy.    Albin.    Werner* 

Colour  several  shades  of  white,  grayish,  bluish  or  red^ 
10* 


1U  SPAR. 

dish.  Streak  white.  Transparent... translucent.  [Lustre 
vitreous,  passing  into  pearly.  Brittle.  Hardness  4.5— 
5.0.  Sp.  gr.  2.33.  It  yields  to  mechanical  division  par- 
allel to  the  planes  of  a  square  prism  ;  most  readily  at  right 
angles  to  the  axis,  or  in  the  direction  of  the  plane  P. 

11.  AXOTOMOUS  KOUPHONE-SPAR. 

Axifrangible,  Zeolite,  or  Apophyllite  (in  part.)    Jam. 
Apophyllile.    Phil. 
Ichthyophthalmites.    Werner. 

Colour  several  shades  of  white.  Streak  white.  Trans- 
parent...translucent.  Lustre  vitreous,  inclining  to  pearly. 
Brittle.  Hardness  4.5 — 5.0.  Sp.  gr.  2.46.  HaUy.  It 
yields  readily  to  cleavage  perpendicular  to  the  axis.  Slight 
traces  of  cleavage  appear  parallel  to  the  axis. 

This  and  the  preceding  species  may  constitute  but  one. 
They  are  provisionally  separated  until  further  examination 
shall  dispel  the  present  uncertainty  in  regard  to  their  constitu- 
tion. 

1.  Before  the  blow-pipe  both  species  exfoliate  and  melt  into 
a  while  vesicular  globule.     They  dissolve  easily  in  borax  and 
then  gelatinize  in  acids.    They  consist  of 

Pyramidal  Kouphone-Spar.        Axotom.  K.  Spar. 

Silex,  52.13  52.38 

Lime,  24.71  24.9S 

Potash,  5.27  5.27 

>..".•     Fluoric  acid,  0.82  0.64 

Water,  16.20  16.20 

Berzelius. 

The  atomic  constitution  maybe  given  as  consisting  of  1  atom 
of  sex-silicate  of  potasli-f  8  atoms  of  tri-silicate  of  lime+16 
atoms  of  water. 

2.  Apophyllite  occurs  in  Faroe,  Uton  and  Nova-Scotia. 

12.  BREWSTERITE.    H.  J.  Brooke. 

Colour  white,  inclining  to  gray  or  yellow.  Streak 
white.  Lustre  vitreous.  Transparent... translucent.  Hard- 
ness 5.0 — 5.5.  Sp.  gr.  2.12 — 2.20.  Cleavage  perfect, 
parallel  to  the  plane  P,  and  apparently  at  right  angles  to 


SPAR. 


115 


it.    Primary  form,  as  deduced  from  the  secondary  planes, 
is  a  right  oblique  angled  prism. 

1.  Before  the  blow-pipe  it  becomes  opake,  then  swells  up 
but  fuses  with  difficulty.  It  gives  a  skeleton  of  talc,  with  salt 
of  phosphorus.  Brewsterite  consists  of 

Silex,  53.66 

Alumine,       17.44 

Strontian, 

Baryta, 

Lime, 

Ox.  iron, 


Water, 


8.32 
6.74 
1.34 
0.29 
12.58 


15.06 


Connell 


Its  atomic  constitution  may  be  expressed  by  2  atoms  of  bi- 
silicate  of  strontia+1  atom  bisilicate  of  baryta-f-12  atoms  trisi- 
licate  of  alumina-f-6  atoms  of  water. 

2.  It  was  formerly  confounded  with  the  prismatoidal  and 
hemi-prismatic  Kou phone-spar.  It  occurs  at  Strontian,  in 
Argyleshire,  associated  with  calcareous  spar. 

13.  COMPTONITE. 
Complonite.    Dr.  Brewster,  Ed.  Phil.  Jour. 

Colour  white.  Streak  white.  Transparent... trans- 
lucent. Lustre  vitreous.  Hardness  5.0 — 5.5.  It  yields 
to  cleavage,  parallel  to  the  lateral  planes  of  a  right  rec- 
tangular prism. 


M 


M  on  T  90°  00' 
T  on  c'  93  00 
c  on  c'  177  5 
Mondl36  35  Phil.  JMm.j>.201.  ] 


1.  Before  the  blow-pipe  it  appears  much  like  other  species 
of  the  Kouphone-spar.     In  nitric  acid  it  gelatinizes. 

2.  It  occurs  lining  cavities  of  an  amygdaloid  rock,  on  Ve- 
suvius. 

14.  GMELINITE.    Brewster. 

Sarcolite.    Vauquelin.     Far.  of  Analcimt.    Haiiy.    Hydrolite  of 
De  Dree. 

Colour  white,  passing  into  flesh-red.     Streak  white. 


116 


SPAR. 


Translucent.  Lustre  vitreous.  Hardness  4.5.  Sp.  gr. 
2.05.  Cleavage  direct,  parallel  to  the  planes  of  a  rhom- 
bohedron.  Fracture  uneven. 

1.  "When  held  in  the  flame  of  a  candle  it  flies  off  in  numer- 
ous scales.    It  yields  by  analysis 

Silex,  50.00 

Alumine,         20.00 
Lime,  4.50 

Soda,  4.50 

Water,  21.00     Vauquelin. 

2.  It  occurs  in  Glenarm,  county  of  Antrim,  Ireland. 

15.  LEVYNE. 

Levyne.    Dr.  Brewster,  Ed.  Jour.  Science. 

Colour  white.  Streak  white.  Semi-transparent.  Lus* 
tre  vitreous.  Brittle.  Hardness  4.0.  Fracture  uneven, 
conchoidal.  Cleavage  indistinct,  parallel  to  the  planes  of 
a  rhombohedron. 

1.  When  heated  in  a  glass  tube  it  gives  off  considerable 
water,  and  becomes  opake.     With  salt  of  phosphorus  it  yields 
a  transparent  globule,  which  contains  a  skeleton  of  silica,  but 
becomes  opake  on  cooling. 

2.  It  occurs  in  Faroe  with  Heulandite  in  amygdaloid, 

MESOLE. 

Mesole.    Berzelius.    Ed.  Phil.  Jour.  vol.  vii.  p.  7. 
Colour  white,  sometimes  inclining  to  yellow.     Faintly 
translucent.     Hardness  3.5.     Sp.  gr.  2.37. 

It  is  composed  of  crystals,  radiating  from  a  centre, 
which  together  form  globular  and  reniform  masses. 

1.  It  consists  of        Silex,  42.60 

Alumine,  28.00 

Lime,  11.43 

Soda,  5.63 

Water,  12.70 

2.  It  is  found  in  Faroe,  lining  the  cavities  in  an  amygda- 
foidal  rock. 


SPAR.  117 

, 

?"         SARCOLITE. 
'Sarcolite  of  Thompson. 

Colour  flesh-red.  Fracture  presents  a  vitreous  appear- 
ance. Hardness  sufficient  to  scratch  glass. 

1.  It  is  supposed  by  Haiiy  to  be  a  variety  of  hexahedral 
Kouphone-spar.  An  accurate  determination  of  this  species  has 
never  been  made. 

THOMPSONITE. 
Thompsonite.    Brooke.    Ann.  of  Phil. 

Colour  white.  Streak  white.  Small  fragments  trans- 
parent. Lustre  pearly.  Brittle.  Hardness  5.0.  Sp. 
gr.  2.37.  Fracture  uneven.  Cleavage  parallel  to  the 
lateral  planes  only  of  a  square  prism. 

1.  It  intumesces  before  the  blow-pipe,  and  becomes  white 
and  opake,  but  does  not  melt. 

It  consists  of         Silex,  36.80 

Alumine,  31.36 

Lime,  15.40 
Magnesia,  0.20 

Perox.  iron,        0.60 

Water,  13.00     Thompson.' 

2.  It  occurs  in  the  Trap  rock  of  Kilpatrick,  near  Dumbarton,, 
in  Scotland. 

GENUS  VI.    PETALINE-SPAR. 

H.=6.0— 6.5 
G.  =2.4—2.5 

1.  PRISMATIC  PETALINE-SPAR. 
Prismatic  Petalite.    Jam.    Petalite.    Phil.     C. 

Colour  white,  in  reddish  and  grayish  shades,  sometimes 
inclining  to  green.  Streak  white.  Translucent.  Lus- 
tre vitreous,  inclining  to  resinous.  Brittle.  Hardness 
6.0 — 6.5.  Sp.  gr.  2.43.  It  yields  to  cleavage  parallel 
to  the  planes,  and  more  distinctly  to  the  long  diagonal  of 
a  prism  of  95°.  Traces  of  cleavage  parallel  to  the  shorter 
diagonal ;  also  perpendicular  to  the  axis. 


118  SPAR. 

1.  It  melts  with  great  difficulty  before  the  blow-pipe,  only 
on  the  edges.  If  gently  heated  it  emits  a  blue  phosphorescent 
light.  It  consists  of 

Silex,  79.21 

Alumina,        17.22 
Lithia,  5.76    Arfwedson. 

It  is  atomically  constituted  of  1  atom  of  sex-silicate  of  lithia 
and  3  atoms  of  tri-silicate  of  alumina. 
It  is  found  at  Bolton,  Mass. 

,  GENUS  VII.    FELD-SPAR. 

H.=5.0— 6.0 
G.=2.5— 2.8 

1.  RHOMBOHEDRAL  FELD-SPAR. 

Rhomboidal  Feldspar  or  Nepheline.    Jam. 
Somnile.    Phil.       Nepheline.    C. 

Colour  white  ;  sometimes  grayish  or  greenish.  Streak 
white.  Transparent... translucent.  Brittle.  Hardness  6.0. 
Sp.  gr.  2.56.  It  cleaves  parallel  to  all  the  planes  of  a 
regular  hexahedral  prism.  Cross  fracture  conchoidal. 

Compound  varieties  often  granular. 

1.  Before  the  blow-pipe  it  fuses  into  a  porous  opake  bead, 
and  gelatinizes  in  nitric  acid. 

It  consists  of   Aluminc,          49. 
Silex,  46. 

Lime,  2. 

Oxide  of  iron,   1.     Vauquelin. 

2.  It  occurs  principally  at  Monte-Somma,  m  the  cavities  of 
limestone  rocks,  ejected  from  Vesuvius, 

2.  PRISMATIC  FELD-SPAR. 

Prismatic  Feldspar.    Jam. 
feldspar.    Phil.    C. 

Colour  white  and  reddish-white,  inclining  to  gray, 
green  and  blue.  Streak  white,  or  grayish-white.  Trans- 
parent...opake.  When  polished  it  presents  a  greenish- 
white  chatoyant  reflection  of  light.  Lustre  vitreous. 
Hardness  6.  Sp.  gr.  2.55.  Limits  of  the  species  2.53 — 


SPAR. 


119 


2.60.  Structure  always  lamellar.  It  yields  to  mechanical 
division  parallel  to  the  plane  of  a  doubly  oblique  prism  of 
the  following  dimensions : 


MonT 

120°  35 

Pon  M 

90 

x 

67    15 

—    cl 

145    20 

—    c2 

129   30 

M  on  c  1 

90 

—  on  i 

150 

—  onkl 

120    30 

—  on  h 

116    35 

T  on  c2 

111    00 

—  on  i 

150    00 

—  onkl 

60    50 

c  1  on  c  2 

164    42 

c2  on  c  3 

150    45 

c  1  on  h 

149    10 

c2  on  h 

152   30 

kl  onk2 

150 

See  Phil.  Min.  p.  1 14.  Hauy. 

\.  The  varieties  of  this  species  require  to  be  noticed  more 
particularly  than  those  of  the  preceding  species.  The  more 
common  forms  of  the  compound  varieties  are  granular  and 
compact  in  different  degrees,  or  in  lamellar  masses  with  tra- 
ces oif  cleavage  more  or  less  distinct.  The  following  are  some 
of  the  most  important  varieties. 

Var.  1.  Adularia.  Colour  white,  bluish-white.  Struc- 
ture perfectly  lamellar.  It  is  the  most  perfect  form  of  the 
mineral. 

Var.  2.  Aventurine  Feldspar.  Colours  various.  It  is 
characterized  by  reflecting  light  more  or  less  strongly  from 
points. 

Var.  3.  Labrador  Feldspar.  It  presents  a  beautiful  play 
of  colours  when  viewed  in  particular  directions. 

Var.  4.  Fetid  Feldspar,  Necronite.  It  possesses  the 
common  characters  of  the  species,  but  when  broken  or  scraped, 
it  exhales  a  fetid  odor. 

Var.  5.     Amazon  Stone.     Colour  apple-green. 

2.  Feldspar  when  placed  on  charcoal  before  the  blow-pipe 
generally  melts  with  difficulty  into  a  blebby,  semi-transparent 
glass.  The  following  varieties  consist  of 


120  SPAR. 

jSdularia.  Labrador  Feldspar. 

Silex,  64.00  55.75 

Alumine,       20.60  26.50 

Lime,  12.00  11.00 

Potash,          14.00  0.00 

Soda,  0.00  4.00 

Oxide  of  iron,  0.00  1.25 

Water,  0.00  0.50 

Prismatic  Feldspar  is  an  essential  element  in  granite  and 
gneiss  ;  here  it  is  abundant  in  nature.  It  passes  by  disinte- 
gration into  an  earthy  form,  resembling  clay,  which  is  called 
porcelain  earth.  Both  the  earth  and  common  feldspar  are  used 
in  the  manufacture  of  porcelain. 

i.  ICE  SPAR. 

Colour  grayish- white,  occasionally  it  is  said  to  occur 
yellowish  or  greenish-white.  Lustre  vitreous.  Very  brit- 
tle. Hardness  6.  Primary  form  a  right  rhombic  prism. 
It  yields  to  mechanical  division  parallel  to  all  the  primary- 
planes,  but  with  difficulty  parallel  to  P,  and  with  ease  to 
T  and  M.  P  on  M  90°  00'.  M  on  T  129°  00'. 

Before  the  blow-pipe  it  fuses  with  difficulty  on  the  edges  into 
a  blebby  transparent  glass. 

ii.  ALBITE. 

Colour  white  or  bluish-white.  Translucent.  Lustre 
vitreous,  inclining  to  pearly.  Streak  white.  Structure 
foliated.  Hardness  6.0.  Sp.  gr.  2.61.  Primary  form  a 
double  oblique  prism,  yielding  angles  of  93°  30'  and  86° 
30'. 

It  usually  occurs  in  thin  rhombic  tables,  one  or  more  of 
the  lateral  edges  are  sometimes  truncated.  A  compound 
variety  consists  of  thin  slender  prisms  applied  to  each  oth- 
er by  the  broad  planes,  which  frequently  radiate  or  form 
stellular  groups.  It  also  occurs  in  granular  masses^  more 
or  less  fine,  resembling  granular  dolomite, 

1.  Before  the  blow-pipe  it  fuses  with  more  difficulty  than 
feldspar,  but  gives  the  same  result. 


SPAR, 


121 


I  consists  of    Silex,  70.7 

Alumine,  19.8 

Soda,  9.0 

Lime,  oxide  of  manganese,  0,3 

It  is  constituted  of  1  atom  of  tri-silicate  of  soda-f-3  atoms  of 
bisilicate  of  alumina.  It  is  usually  associated  with  blue,  green 
and  red  tourmaline,  in  the  coarser  granites.  It  is  better  known 
under  the  name  of  Cleavelandite. 

It  is  found  at  Chesterfield,  at  the  celebrated  tourmaline  lo- 
cality, at  Chester,  Mass,  and  at  Brunswick,  Me. 

3.  PYRAMIDAL  FELD-SPAR. 

Pyramidal  Feldspar,  or  ^capolite.    Prismato- Pyramidal  Feldspar,  or 
Miconilz.    Jam.     Dipyne.     Scapolite.    Miconite.    Phil. 

Colour  various  shades  of  gray,  white  and  green,  and 
red  and  purple.  Streak  grayish- white.  Transparent., 
translucent  on  the  edges.  Lustre  vitreous,  inclining  to 
pearly.  Brittle.  Hardness  5.0 — 5.5.  Sp.  gr.  2.61.  It 
yields  to  cleavage  parallel  to  the  sides,  terminal  planes 
and  both  diagonals  of  a  square  prism. 


M  on  M'  90°  00' 

M  or  M'  on  d  135  00 

M  on  a  112  30 

a  on  d  122  10 


M 


1.  Before  the  blow-pipe  it  fuses  with  a  lively  intumescence 
into  a  light  spongy  mass.     It  consists  of 

Silex,  40.53 

Alumine,  32.72 

Lime,  24.00 

Potash  and  soda,  1.81 

Protoxide  of  iron,         0.18     Stromeyer. 
It  is  constituted  atomically  of  1  atom  of  silicate  of  lime+3 
atoms  of  silicate  of  alumina. 

2.  Pyramidal  Feldspar  occurs  in  Bolton  and  Chester,  Mass. 
At  the  latter  place  it  occurs  in  veins  in  mica  slate,  associated 
with  hornblende,  pyroxene  and  garnet  5  but  the  crystalization 

11 


122  '  SPAR. 

is  generally  confused  and  indistinct.  Fine  specimens  are 
found  at  Chelmsford,  Mass,  and  at  Warwick,  Orange  co, 
N.Y, 

4.  ANORTHITE. 
Anorthit.    G.  Rose.     Gilbert's  Ann.  der  Physik,  1823. 

Colour  white.  Streak  white.  Lustre  pearly  upon 
cleavage  planes:  Transparent... .translucent.  Brittle. 
Hardness  6.0.  Sp.  gr.  2.76. 

1.  Before  the  blow-pipe  it  appears  like  Feldspar.     It  is  en- 
tirely decomposed  by  concentrated^muriatic  acid. 

It  consists  of         Silex,  44.49 

Alumina,          34.46 
Lime,  15.68 

Magnesia,          5.26 
Oxide  of  iron,    0.74 

2.  It  occurs  only  at  Mount  Vesuvius,  associated  with  para- 
tomous  Augite-spar. 

5.  LATROBITE. 
Latrobile.    Brooke.    Ann.  of  Phil.  xxix.  p.  383. 

Colour  pale  pink-red.  Hardness  5.0 — 6.0.  Sp.  gr.  2.8. 
It  cleaves  in  three  directions,  parallel  to  the  planes  of  a 
doubly  oblique  prism,  at  angles  of  98°  3',  91°  and  93°  30'. 

1.  Alone  before  the  blow-pipe  it  fuses  into  a  white  enamel. 
With  borax  it  yields  a  globule,  pale-red  in  the  oxidating  flame, 
and  colourless  in  the  reducing  one.     With  salt  of  phosphorus 
it  gives  a  silica  skeleton. 

It  consists  of    Silex,  44.65 

Alumine,  36.81 

Lime,  8.29 
Oxide  of  manganese 

and  magnesia,  3.78 

Potash,  6.57 

Water,  2.04 

2.  It  occurs  at  Amitok  island,  near  the  coast  of  Labrador. 


SPAR, 


123 


GENUS  VIII.    AUGITE-SPAR. 

H=4.5-7.0 
0=2.7—3.5 

1.  PARATOMOUS  AUGITE-SPAR. 

Oblique-edged  Augit  e.    Jam. 
Augite.    Pyroxene.    Phil.    C. 

Colour  green,  often  inclining  to  brown,  and  passing  in- 
to gray  and  white,  and  also  black.  Streak  white — gray, 
or  corresponding  to  the  colour.  Faintly  transparent... 
opake.  Lustre  vitreous,  inclining  to  resinous.  Brittle. 
Hardness  5.0 — 6.0.  Sp.  gr.  of  a  light  coloured  specimen 
3.32.  It  yields  to  cleavage  parallel  to.  the  planes  of  an 
oblique  rhombic  prism,  of  87°  5'  and  92°  55'. 


^- 

\ 
s 

T> 

\ 

M 

r 

M 

\ 

.,--'" 

\ 

M 


M 


M  on  M  87°  42' 
M  on  P  101  5 
M  on  r  133  51 
M  on  s  121  48 

Troost.    Jour.  Jfat.  Sci.  vol.  iii,  p.  120. 

1.  Under  paratomous  Augite- spar  a  great  number  of  vari- 
eties are  placed.  The  following  are  the  important  ones. 

Var.  1.  Augite,  comprehends  those  opake  varieties,  the 
colours  of  which  are  green  or  blackish-green  ;  it  occurs  foliat- 
ed and  in  grains.  The  former  is  distinguished  by  the  name 
of  sahlite,  the  latter  by  the  name  of  coccolite.  The  colours  are 
however  very  numerous,  passing  through  a  series  of  colours 
from  very  dark-green  or  black,  red,  gray  and  grayish-white. 


124  SPAR- 

2.  Diopside.     Colour  greenish- white  or  greenish-gray.    It 
occurs  in  semi-transparent  crystals. 

3.  Baikalite.     Closely  resembles  sahlite,  and  can  hardly 
be  distinguished  from  it. 

4.  Fassaite  possesses  a  greenish-yellow  colour  and  presents 
the  same  crystaline  forms  as  diopside. 

5.  Omphazite  is  a  compact  leek-green  variety  with  a  splin- 
tery fracture.    It  often  passes  into  a  fibrous  structure,  forming 
one  variety  of  asbestus. 

6.  Jeffersonite,  which  is  of  a  dark-brown  colour  arising  from 
the  mechanical  mixture  of  oxides  of  iron  and  manganese. 

2.  Paratomous  Augite-spar  consists  of 

Silex,  54.08 

Lime,  23.19 

Magnesia,  11.49 

Protoxide  of  iron,        10.02 
Oxide  of  manganese,    0.61 

Leek-green  variety  analized  by  Rose, 

The  darker  specimens  contain  a  greater  per  cent  of  iron, 
the  lighter  a  less  per  centage. 

The  atomic  constitution  of  paratomous  Augite-spar  may  be 
expressed  by  1  atom  of  bisilicate  of  lime+1  atom  of  bisilicate 
of  magnesia.  The  bisilicate  of  magnesia  is  sometimes  replac- 
ed by  bisilicate  of  protoxide  of  iron,  as  in  the  Euchysiderite 
and  Jeffersonite.  Its  composition  is  greatly  influenced  by  the 
adjacent  rock  in  which  it  occurs. 

This  mineral,  particularly  Sahlite,  is  found  in  Munroe  and 
Warwick.  Sahlite  and  Coccolite  of  different  colours  are  found 
near  Roger's  Rock,  N.  Y.  also  at  Middlefield,  Chester,  Hins- 
dale,  and  in  most  of  the  mountain  towns  in  New-England,  in 
specimens  more  or  less  perfect. 

2.  HEMI-PRtSMATtC  AUGITE-SPAR. 

Strait  edged  Augile.    Green  Diallage.    Jam. 
Hornblende.    Smaragdite.    Asbtslus.    Phil.    C. 

Colour  various  shades  of  green,  often  inclining  to  brown. 
The  series  of  colours  form  an  uninterrupted  passage  from 
perfectly  white  and  green  into  black.  Streak  gray-brown. 
Lustre  vitreous,  often  inclining  to  pearly  ;  dull  in  the 
darker  varieties.  Slightly  translucent... opake.  Brittle. 


SPAR. 


125 


Hardness  5.0 — 6.0.  Sp.  gr.  of  a  dark  variety  3.16.  It 
yields  to  cleavage  parallel  to  the  plane  of  a  rhombic  prism 
of  124°  30'  and  55°  30'.  Primary  form  an  oblique  rhom- 
bic prism  of  the  following  dimensions  : 


Primary  form. 


MonM' 

MorM'  onP  103 
M'onk  117 

Pongorg'  145 
M  on  g  or  g'  68 
g  on  g'  148 


124°  30' 
1 

32 
43 
42 
22 


Compound  varieties.  Composition  granular,  often  form- 
ing an  extremely  cohesive  mass,  with  a  slaty  and  colum- 
nar composition.  It  often  occurs  forming  mountain  mass- 
es. Crystaline  masses  are  usually  composed  of  long  and 
delicate  fibres,  of  a  silky  lustre — they  are  straight,  paral- 
lel and  divergent,  and  often  form  fascicular  and  scopiform 
groups. 

1.  Before  the  blow-pipe  this  mineral  fuses  with  intumes- 
cence without  addition,  into  a  glass  more  or  less  coloured,  cor- 
responding much  to  the  colour  of  the  specimen.  The  elements 
entering  into  the  composition  of  some  of  the  varieties  are  as 
follows : 

A  green 
var. 

46.26 
19.03 
13.96 
11.48 

3.43 

9.36 

1.60 


Silex, 
Magnesia, 
Lime, 
Alumina, 
Protoxide  of  iron, 

"     manganese, 
Fluoric  acid, 
Water  and  foreign 

substances, 


A  white 
var. 

60.31 

24.23 

13.16 

0.26 

0.15 

0.00 

0.94 


Smarag- 
dite. 


A  black 
var. 

45.69  50.00 

18.70  6.00 
13.85                13.00 
12.18                11.00 

7.32  ox.  iron,  5.05 
0.22  do  copper,  1.50 
1.50  do  chrome,  7  50 


0.10        1.04        0.00 


The  different  varieties  of  hornblende  are  considered  as  bisili- 
cates  of  lime  and  magnesia.  The  variation  in  the  chemical 
constitution  depends  much  on  the  rock  with  which  they  are  con- 
nected. 

11* 


126  SPAR. 

Under  this  species  are  placed  a  number  of  minerals  which 
were  formerly  considered  as  distinct.  Under  the  name  horn- 
blende are  comprehended  the  dark-green  varieties,  having  but 
little  lustre,  and  a  substance  which  is  extremely  tough  in  the 
mass,  but  separate  crystals  are  brittle.  Actynolite  is  a  bright 
green  var.  always  crystalized,  and  usually  in  long  slender 
prisms.  It  is  found  imbedded  in  talcose  rocks.  Tremolite  is 
a  white  variety,  and  is  usually  crystalized  in  what  are  termed 
Haded  crystals.  It  is  found  imbedded  in  dolomite.  These 
varieties  all  pass  into  asbestus,  forming  each  of  them  a  variety. 
Hornblende  forms  mountain  masses,  and  is  abundant.  Acty- 
nolite is  found  at  Middlefield,  Worthington  and  Cummington, 
Mass.  Newfane,  Vt.  Tremolite  is  found  abundantly  in  Shef- 
field and  several  other  towns  in  the  county  of  Berkshire,  Mass. 
and  in  Litchfield  county,  Ct. 

The  finest  specimens  of  all  the  varieties  are  found  in  War- 
wick, Orange  county,  N.  Y.  sometimes  in  detached  boulders, 
and  in  other  cases  in  carb.  of  lime.  A  beautiful  reddish-brown 
hornblende  occurs  near  the  church  at  Amity,  both  in  crystal- 
ized and  in  granular  masses. 

3.  PRISMATOIDAL  AUGITE-SPAR. 
Prismatoidal  Augite..    Jam.    Epidote.    Phil.     C. 

Prevailing  colours  green  and  gray  ;  the  green  tints  in- 
cline more  to  yellow  than  in  pyroxine  or  hornblende, 
rarely  white  or  flesh-red.  Streak  white.  Semi-trans- 
parent... opake.  Lustre  vitreous.  Brittle.  Hardness 
6.0 — 7.0.  Sp.  gr.  3.26.  Primary  form  a  right  oblique 
angled  prism.  M  on  T  115°  40'.  (For  fig.  see  garnet 
in  the  order  Gem,  marked  fig.  4,  and  referred  back  to  this 
place.) 

Compound  varieties — Massive,  structure  granular,  often 
friable  and  arenaceous. 

1.  Before  the  blow-pipe  it  fuses  with  intumescence  into  a 
transparent  glass.  It  consists  of 

Silex,  37.00 

Alumine,  27.00 

Lime,  14.00 

Oxide  of  iron,        3.00 
"    manganese,  1.50    Descot. 


SPAR.  127 

2.  Prismatoidal  Augite-Spar  occurs  in  primitive  rocks,  more 
especially  in  Hornblende. 

It  is  found  at  Franconia,  N.  H.  in  fine  specimens  ;  Chester, 
Middlefield,  Cummington,  Worthington  and  Plainfield,  Mass. 

6.  ZOISITE. 

Colour  gray,  or  grayish-yellow.  Translucent... opake. 
Streak  grayish  white.  Lustre  vitreous.  Hardness  6.0 — 
7,0.  Sp.  gr.  3.26.  Primary  form  a  right  rhombic  prism. 
M  on  M'  116°  30',  and  apparently  a  cleavage  transverse  to 
the  axis,  but  not  sufficiently  distinct  for  measurement, 
which  indicates  that  the  prism  is  oblique  from  an  obtuse 
edge.  Brooke.  Crystals  deeply  striated  longitudinally. 

Before  the  blow-pipe  Zoisite  behaves  very  much  like  pris- 
matoidal  Epidote.  Some  varieties  intumesce  and  form  a  yel- 
lowish scoria. 

It  is  found  at  Brattleborough,  Vt.  and  Hawley,  Chester- 
field, Mass. 

6.  PRISMATIC  AUGITE-SPAR. 

Prismatic  rfugite,  or  Tabular-Spar.    Jam. 
Tabular- Spar.    Phil.  C.     Schalstein.    Werner. 

Colour  white,  inclining  to  gray,  yellow,  red  and  brown. 
Streak  white.  Semi-transparent... opake.  'Lustre  vitre- 
ous, inclining  to  pearly,  particularly  on  the  faces  of  cleav- 
age. Brittle.  Hardness  4.0—5.0.  Sp.  gr.  2.80.  It  ib 
divisible  into  prisms  of  95°  20'  and  84°  40',  and  also  par- 
allel to  both  diagonals.  Primary  form  a  double  oblique 
prism.  M  on  T  95°  20'. 

1.  Before  the  blow-pipe  it  fuses  with  a  strong  heat  into  a 
colourless  glass. 

It  consists  of  Silex,  50 

Lime,  45 

Water,  5 

2.  It  occurs  in  the  county  of  Essex,  N.  Y.  and  in  Easton, 
Penn.     Some  localities  furnish  specimens  much  resembling 
tremotite. 


128  SPAR. 

GENUS  IX.    AZURE-SPAR. 

H.=5.0— 6.0 
G.=2.9— 3.1 

1.  DODECAHEDRAL  AZURE-SPAR. 

Azure,  Stone,  or  Lapis  Lazuli.    Jam.    Phil.   C. 

Colour  various  shades  of  azure-blue,  not  uniform  but 
appearing  in  spots.  Streak  blue,  paler  than  the  colour. 
Translucent  on  the  edges.  Lustre  vitreous.  Brittle. 
Hardness  5.5 — 6.0.  Sp.  gr.  2.95. 

1.  Before  the  blow-pipe  it  melts  with  difficulty  into  a  glass 
globule,  which  is  first  of  a  bluish  tinge,  but  soon  becomes 
white.  If  previously  burnt  and  reduced  to  powder,  it  loses  its 
colour  and  forms  a  jelly  with" acids.  It  consists  of 

Silex,  49        Silex,  46 

Magnesia,  2        Alumine,  14 

Alumina,  11         Carb.  lime,  28 

Lime,  16        Sulphate  of  lime,        6.5 

Potash  and  soda,          8        Oxide  of  iron,  3 

Oxide  of  iron,  4        Water,  2 

Sulphuric  acid,  2  Klaproth. 

Gmelin. 

It  occurs  in  primitive  rocks,  but  its  particular  geological 
relations  are  unknown.  It  is  valuable  chiefly  as  affording  a 
pigment,  called  ultra-marine,  which  is  not  liable  to  change  by 
time  and  exposure.  The  finest  specimens  come  from  China 
and  Persia. 

2.  PRISMATIC  AZURE-SPAR. 

Jlsurite.    Lazulite.  Phil. 

Prismatic  Azure-Spar,  (first  sub-species.)    Jam. 

Colour  fine  deep  blue  when  viewed  in  the  direction  of 
the  axis  of  the  crystals,  but  various  shades  in  other  direc- 
tions* Streak  white.  Lustre  vitreous  Brittle.  Hardness 
5.0 — 5.5.  Cleavage  indistinct.  Primary  form  a  right 
rhombic  prism.  M  on  M  121°  30', 

1.  Before  the  blow-pipe  it  intumesces,  but  does  not  melt. 
With  borax  it  yields  a  clear  colourless  globule.  Treated  with 
boracic  acid  and  iron  wire,  it  gives  a  globule  of  phosphuret  of 
iron.  Berzelius.  It  consists  of 


SPAR.  129 

Phosphoric  acid,  41.81 

Alumina,  35.73 

Magnesia,  9.34 

Silex,  2.10 

Protoxide  of  iron,  2.64 

Water,  6.00    Fuchs. 

It  has  been  found  in  Salzburg,  in  narrow  veins,  traversing 
clay  slate,  both  massive  and  crystalized. 

3.  PRISMATOIDAL  AZURE-SPAR. 

Blue  Feldspar.    Phil. 

Prismaloidal  Azure-Spar,  or  Blue-Spar.    Jam. 

Colour  smalt-blue,  inclining  to  white  or  green  on  the 
faces  of  cleavage.  Lustre  vitreous.  Streak  white.  Trans- 
lucent on  the  edges  ;  often  nearly  opake.  Brittle.  Hard- 
ness 5.5- — 6.0.  Sp.  gr.  3.02.  Fracture  splintery. 

Compound  varieties  present  a  granular  composition,  of- 
ten in  large  individuals. 

1.  Before  the  blow-pipe  it  loses  colour,  but  does  not  melt. 

It  is  slowly  and  difficultly  dissolved  in  borax.     It  consists  of 

nearly  the  same  elements  as  the  preceding  species. 

Phosphoric  acid,  43.32 

Silex,  6.50 

Alumina,  34.50 

Magnesia,  13.56 

Lime,  00.48 

Protoxide  of  iron,  00.80 

Water,  00.50 

It  occurs  in  the  valley  of  Freschnitz,  on  the  Miirz,  in  Up- 
per Stiria,  associated  with  quartz  and  mica. 

The  following  species  belong  to  the  order  Spar,  but  their 
properties  have  not  been  sufficiently  investigated  to  give  them 
a  place  in  the  system  under  appropriate  names. 

1.  ACMITE. 

Colour  brownish-black.  Streak  pale  yellowish-gray  ; 
opake  ;  very  thin  edges  are  translucent,  and  show  a 
fine  yellowish-brown  tint.  Brittle.  Hardness  6.0 — 6.5. 
Sp.  gr.  3.24. 


130  SPAR. 

1.  It  resembles  paratomous  Augite-spar  in  regard  to  form 
and  composition.  It  melts  readily  before  the  blow-pipe  into  a 
blackish  globule. 

It  consists  of  Silex,  55.25 

Oxide  of  iron,  31.25 

"  manganese,          1.08 
Lime,  0.72 

Soda,  10.40    Berzetius. 

It  is  fotfnd  at  Eger,  in  Norway,  imbedded  in  granite. 

2.  ARFVEDSONITE. 

Arfvedsonite.    Brooke*     Ann.  Phil.  numb.  xxix.  p.  381. 

Colour  black.  Sp.  gr.  3.44.  Brooke.  Cleavage  par- 
allel to  the  planes  of  a  rhombic  prism  of  123°  55',  with 
brilliant  surfaces. 

1.  It  melts  easily  before  the  blow-pipe  into  a  black  globule. 
With  borax  it  gives  a  glass  coloured  with  iron.     With  salt  of 
phosphorus  it  dissolves,  leaving  a  dark-gray  skeleton  of  silex. 

2.  It  occurs  in  Greenland,  and  accompanies  the  dodecahe- 
dral  Kouphone-spar. 

3.  BABINGTONITE. 
Babingtonite.    Levy.     Ann.  of  Phil.  xl.  p.  275. 

Colour  black,  or  greenish  in  thin  splinters,  which 
are  faintly  translucent.  Opake  in  large  masses.  Lustre 
vitreous.  Hardness  5.5 — 6.0. 

1.  It  resembles  the  darker  coloured  varieties  of  paratomous 
Augite-spar.    It  consists  of  silica,  oxide  of  iron,  lime,  manga- 
nese and  a  trace  of  titanium. 

2.  It  occurs  in  small  crystals  at  Arendal,  in  Norway,  ae 
sociated  with  albite. 

4.  INDIANITE. 

Colour  greenish-white.  Translucent.  Scratches  glass. 
Sp.  gr.  2.74.  Occurs  in  grains  which  have  a  cleavage  in 
two  directions,  forming  an  angle  of  95°  15'.  Brooke. 

1.  It  is  infusible  before  the  blow-pipe.     If  digested  in  acids 
it  becomes  friable  and  gelatinous.     It  consists  of 
Silex,  42.50 

Alumina,  37.50 

Lime,  15.00 

Oxide  of  iron,          3.00 


SPAR.  131 

2.  It  occurs  in  the  Carnatic,  imbedded  in  prismatic  Feld- 
spar, and  accompanied  by  rhombohedral  corundum. 

5.  WITHAMITE. 
Withamite.    Brewster.    Ed.  Jour,  of  Science,  vol.  ii.  p.  218. 

Colour  carmine-red  and  pale  straw-yellow.  Streak 
white.  Translucent.  Brittle.  Hardness  6.0—6.5.  Sp. 
gr.  3.13. 

1.  Before  the  blow-pipe  it  intumesces,   but  fuses  with  dif- 
ficulty into  a  dark  gray  scoria.     Salt  of  phosphorus  dissolves 
it  with  effervescence  into  a  globule,  which  contains  silica,  and 
becomes  opake  on  cooling.     It  shows  nearly  the  same  reaction 
as  the  Epidote  from  Arendal,  with  which  it  agrees  in  most 
of  its  other  properties. 

2.  It  occurs  at  Glencoe,  in  Scotland,  in  a  reddish  trap- 
rock.     Haidinger. 

6.  AMBLYGONITE. 
Amblygonile.    Jam.    Phil.    C.    , 

Colour  greenish-white,  passing  into  light  mountain- 
green,  or  sea-gfeen.  Streak  white.  Semi-transparent.,, 
translucent.  Hardness  6.0.  Sp.  gr.  3.00.  It  occurs  in 
rhombic  prisms,  which  are  rough  externally.  Inclination 
of  M  on  M'  106°  10'.  It  affords  brilliant  planes  by 
cleavage. 

1.  Before  the  blow-pipe  it  intumesces  and  is  fused  with  ease, 
and  is  converted  into  a  white  enamel. 

It  consists  of  alumine,  phosphoric  and  fluoric  acids  and 
lithia,  in  greater  quantities  than  any  other  mineral.  Berzetius. 

It  has  hitherto  been  found  only  at  Chursdorf,  near  Penig,  in 
Saxony,  in  granite. 

7.  BERGMANITE. 

Bcrgmanite.  Jam.  Phil.  (Var.  of  Pyramidal  Feldspar  or  Scapolite.) 
Colour  gray,  passing  into  white  and  brick-red.  Opake. 
Massive.  Not  very  brittle.  Soft,  passing  into  semi- 
h  zrd.Breithaupt.  Lustre  pearly.  Composition  thin, 
columnar.  Scratches  glass,  and  even  quartz. 
Sp.  gr.  2.3, 


,132  SPAR. 

1.  Before  the  blow-pipe  it  becomes  white,  and  then  melts 
without  effervescence  into  a  colourless  glass.  It  occurs  near 
Stavern,  in  Norway. 

8.  BUCKLANDITE. 
Bucklandite.    Levy.    Ann.  of  Phil.  Feb.  1824,  p.  134. 

Colour  dark-brown,  nearly  black.  Opake.  Scratches 
paratoraous  Augite-spar.  Cleavage  unknown. 

It  occurs  near  Arendal,  in  Norway,  and  resembles  parato- 
mous  Augite-spar. 

9.  CALAITE. 

Calaite,  or  Mineral  Turquoise.    Jam. 
Turquoise.    C. 

Colour  blue,  passing  into  green,  rather  bright.  Streak 
uncoloured.  Translucent  on  the  edges.  Opake.  Lus- 
tre of  polished  specimens  pearly.  Fracture  conchoidal. 
Hardness  6.0.  '  Sp.  gr.  2.83 — 3.00.  Massive.  Fisher. 

1.  Before  the  blow-pipe  it  becomes  brown  in  the  reducing 
flame,  and  imparts  to  it  a  green  colour.     Infusible  per  se,  but 
fuses  easily  with  borax  and  salt  of  phosphorus. 
It  consists,  according  to  John,  of 

Alumine,  44.50 

Phosphoric  acid,  30-90 

Oxide  of  copper,  3.75 

Water,  19. 

It  occurs  in  alluvial  soil,  in  globular  and  reniform  masses, 
from  the  size  of  a  nut  to  that  of  a  goose-egg.  It  is  found  in 
Persia.  It  is  cut  and  polished  for  ring-stones,  and  other  or- 
namental pieces. 

10.  CHIASTOLITE. 

C9lour  white,  yellowish-white,  gray  and  yellowish- 
gray.  Lustre  indistinctly  vitreous,  passing  into  resinous. 
Streak  white.  Fracture  conchoidal  and  splintery ;  cross- 
fracture  exhibits  a  black  cross.  Hardness  5.0 — 5.5. 
Sp.  gr.  2.94. 

Before  the  blow-pipe  the  whitish  part  is  infusible,  but  a*- 


SPAR.  133 

sumes  a  whiter  colour.  With  borax  and  salt  of  phosphorous  it 
melts  with  difficulty. 

It  is  a  compound  of  alumine  and  silex,  but  it  is  almost  im- 
possible to  determine  the  proportions  of  its  elements.  It  oc- 
curs imbedded  in  clay  slate. 

2;  It  is  found  in  Sterling,  Mass.,  Charlestown,  N.  HM 
Brunswick,  Me. 

11.  DIASPORE. 
Diaspore.    Phil.     C. 

Colour  greenish-gray.  Translucent  on  the  edges. 
Lustre  vitreous,  inclining  to  pearly.  Scratches  glass. 
Sp.  gr.  3.43.  Primary  form  a  doubly  oblique  prism  of 
the  following  dimensions :  M  on  T  64°  54'.  P  on  T 
101°  20'.  P  on  M  108°  30'. 

1.  Before  the  blow-pipe  it  decrepitates  most  violently  and 
splits  into  many  small  scaly  particles,  which  possess  the  pro- 
perty of  changing  the  vegetable  blues  to  green.  According  to 
Vauquelin's  analysis,, it  consists  of 

Alumina,  80. 

Protoxide  of  iron,  3.00 

Water,  17. 

Berzelius  supposes  that  it  contains  an  alkali.  Locality  un- 
known. Rare. 

12.  EUDIALYTE. 

Colour  red,  or  brownish-red.  Translucent.  Lustre 
vitreous.  Fracture  uneven.  Streak  white.  Hardness 
5.0 — 5.5.  Sp.  gr.  2.89.  The  cleavage  gives  a  regular 
hexahedral  prism,  affording  by  measurement  angles  of 
120°  of  one  lateral  plane  on  the  next,  and  90°  of  the 
summit,  on  each  lateral  plane. 

1.  Before  the  blow-pipe  it  melts  into  a  leek-green  scoria. 

If  reduced  to  powder  it  gelatinizes  with  acids.    It  consists  of, 

Silex,  52.00 

Zirconia,  10.89 

Lime,  10.14 

Soda,  13.92 

Oxide  of  iron,  6,85 

12 


134  SPAR. 

Oxide  of  manganese,       2.57 
Muriatic  acid,  1.03     Stromeyer. 

2.  It  is  found  in  Greenland,  mixed  with  dodecahedral  Kou- 
phone-spar,  and  hemi-prismatic  Augite-spar. 

13.  GEHLENITE. 
Gehlenite.    Phil.    Jam.     C. 

Colour  dark-gray,  varying  in  kind,  but  never  bright. 
Lustre  resinous.  Opake.  Sometimes  faintly  translucent 
in  thin  fragments,  Brittle.  Hardness  5.5 — 6.  Sp.  gr. 
3.02.  Crystalizes  in  rectangular  prisms,  differing  but 
little  from  the  cube.  Sometimes  they  are  tabular* 

1.  It  fuses  with  difficulty  before  the  blow-pipe.     It  gelatin- 
izes in  warm  muriatic  acid.     It  consists  of 
Alumine,  24.80 

Silex,  29.64 

Lime,  35.30 

Oxide  of  iron,  6.56 

Water,  3.30    FuchsJ 

It  is  found  in  the  valley  of  Fassa,  in  the  Tyrol,  imbedded  in 
calcareous  spar. 

14.  HAUYNE. 
Hauyne.    Phil.    Jam.     C. 

Colour,  when  opake,  indigo-blue;  when  translucent7 
bluish-green;  usually  bright.  Streak  white.  Translu- 
cent. Opake.  Fracture  uneven.  Scratches  glass.  Sp. 
gr.  2.68,  Gmelin — 3.33,  Gismondi.  Crystalizes  in  the 
form  of  a  rhombic  dodecahedron. 

1.  Before  the  blow-pipe  it  loses  its  colour  and  melts  into  a 
vesicular  glass.   It  effervesces  with  borax  and  melts,  and  forma 
on  cooling  a  yellow  glass. 

It  consists  of      Silex,  35.4S 

Alutnine,  18.87 

Lime,  12.00 

Sulphuric  acid,  12.39 

Potash,  15.45 

Oxide  iron  and  water,  2.36 

2.  It  occurs  at  Albano  and  Frescati,  ne,ar  Rome,  among  the 
products  of  Vesuvius. 


SPAR.  135 

\ 

15.  KARPHOLITE. 

Colour  high  straw-yellow,  passing  into  wax-yellow. 
Opake.  Lustre  silky.  Hardness  low.  Sp.  gr.  2.93. 
Massive.  Composition  thin  columnar,  and  forming  scopi- 
form  and  stellular  groups,  which  are  rather  incoherent. 

1.  It  intumesces  before  the  blow-pipe,  becomes  white,  and 
melts  into  a  coherent  mass.     It  consists  of 

Silex,  37.53 

Alumine,  26.48 

Protoxide  of  manganese,  1 17.09 
Do.         iron,  5.64 

Water,  11.36     Steinmann. 

2.  It  occurs  in  granite  in  Bohemia. 

The  Cummingtonite  is  considered  by  some  mineralogists  as 
a  variety  of  Karpholite.  The  conjecture  needs  stronger  proofs 
than  any  which  have  been  given. 

16.  NEPHRITE.    Jade. 

Colour  green,  particularly  leek-green,  passing  into  gray 
and  white.  Translucent;  often  only  on  the  edges. 
Tough.  Fracture  splintery.  Hardness  7.0.  Sp.  gr. 
2.93 — 3.02.  Massive.  Composition  impalpable  in  the 
mass. 

1.  Alone  before  the  blow-pipe  it  is  infusible.     It  consists  of 

Silex,  50.50 

Magnesia,  31.00 

Alumina,  10.00 

Oxide  of  iron,  5.50 

Do        chrome,        0.05 
Water,  2.75     Kostner. 

2.  It  is  found  at  Smithfield,  R.  I.,  and  at  Easton,  Pa.,  im- 
bedded in  limestone.     Its  extreme  toughness  renders  it  suita- 
ble for  the  handles  of  various  instruments,  and  also  for  deline- 
ating delicate  figures,  without  danger  of  fracture. 

17.  SAUSSURITE. 

Colour  leek-green,  passing  into  blue,  white  and  ash- 
gray.  Lustre  pearly,  inclining  to  vitreous  on  the  faces  of 
cleavage,  resinous  on  a  polished  surface.  Streak  white. 


136  SPAR. 

Broken  with  difficulty.  Hardness  5.5.  Sp.  gr.  3.25. 
Fracture  uneven.  Cleavage  in  two  directions,  affording 
an  angle  of  124°. 

1.  Before  the  blow-pipe  it  melts  with  difficulty  into  a  white 
glass. 

It  consists  of  SHex,  49. 

Alumine,         24. 
Lime,  10. 

,  Magnesia,         3,75 

Oxide  of  iron,    6.50 
Soda,  5.50     Saussure. 

2.  This  mineral  occurs  in  primitive  mountains,  and  consti- 
tutes, with  several  species  of  Augite-spar,  the  rock  called 
gabbro,  and  euphotide.     It  occurs  at  Monte  Rosa,  and  its 
neighborhood. 

18.  SOMERVILLITE. 
Somervillite.    Brooke.     Brand's  Quar.  Jour. 

Colour  pale  dull  yellow.  Hardness  equals  that  of 
ieldspar. 

It  decrepitates  before  the  blow-pipe,  and  melts  alone  into  a 
gray  coloured  globule,  and  with  borax  into  a  colourless  glass. 
It  occurs  at  Vesuvius. 

19.  THULtTE. 

Thuliie.     Brooke's  Crystalography. 

Colour  rose-red.  Streak  grayish-white.  Less  hard 
than  quartz,  but  yields  to  the  knife  with  difficulty.  It 
yields  to  cleavage  parallel  to  the  sides  of  a  rhombic  prism 
of  92o  30' and  87°  30'. 

Occurs  in  Norway ;  resembles  and  may  be  a  variety  of 
manganese-spar. 

20.  MANGANESE-SPAR. 

Siliciferous  Oxide  of  Manganese.    Phil. 

Colour  rose-red.  Translucent  on  the  edges.  Lustre 
intermediate  between  pearly  and  resinous.  Hardness 
5.0 — 5.5.  Sp.  gr.  3,53.  Berzelius.  Massive.  Com- 


SPAR.  137 

position  fine  granular,  and  strongly  coherent.     Cleavage 
apparent,  in  two  directions,  and  forming  an  angle  of  87°  5'. 

1.  Before  the  blow-pipe  it  becomes  dark-brown,  and  melts 
into  a  reddish-brown  globule.     It  imparts  to  glass  of  borax  in 
the  oxidating  flame  a  hyacinth-red,  but  in  the  reducing  flame 
it  remains  white. 

It  consists  of   Silex,  48.04 

Oxide  of  manganese,  54.00 
Oxide  of  iron,  a  trace. 

Lime  and  magnesia,    3.34 

2.  It  occurs  at  Longlanshy ttan,  in  Sweden,  in  beds  of  iron 
ore. 

The  minerals  called  Attagite,  Corneous  Manganese,  Photi- 
zite  and  Rhodonite,  are  said  to  be  compact  varieties  of  the  pre- 
ceding species. 

21.  BIS1LICATE  OF  MANGANESE. 

Binlicate,  of  Manganese.    Thompson.    Ann.  of  the  Lyceum  of  N. 
York,  for  April,  1828. 

Colour  rose-red,  which  on  expose  to  air  becomes  dark 
and  almost  black  on  the  surface.  Surface  often  covered 
with  a  black  crust,  which  is  easily  removed  in  scales. 
Sp.  gr.  3.53. 

1.  It  consists  of  Silex,  40.58 

Protoxide  of  manganese,  38.92 
Protoxide  of  iron,  13.50 

Water,  3.00 

Carbonic  acid,  3.23 

The  peculiarity  furnished  by  this  variety  is,  that  a  portion  of 
the  Protoxide  of  manganese  is  replaced  by  an  equal  quantity 
of  Protoxide  of  iron.  This  mineral  effervesces  slightly  in 
acids,  from  the  presence  of  a  small  quantity  of  carbonate  of 
iron. 

The  Bisilicate  of  manganese  does  not  differ  essentially  from 
Manganese-spar,  the  preceding  mineral.  It  is  introduced  for 
the  purpose  of  giving  the  results  of  the  investigations  of  Prof. 
Thompson. 

2.  It  occurs  in  loose  boulders,  in  Cummington,  Mass.    It 
is  geologically  connected  with  the  hornblende  rock. 

12* 


138  SPAR. 

22.  SILICATE  OF  MANGANESE. 
Silicate  of  Manganese.    Thompson.    Ann.  Lyceum  for  April,  1828. 

Colour  light  brownish-red,  pale  straw-yellow.  Trans- 
lucent on  the  edges.  Streak  light-red  or  yellow.  Lus- 
tre shining  and  vitreous.  Hardness  6.0.  Sp.  gr.  4.07. 
Thompson.  Fracture  foliated.  Cleavage  in  two  direc- 
tions, which  gives  a  prism  slightly  oblique,  affording  by 
measurement  angles  of  86°  and  94°,  with  the  common 
goniometer.  Another  cleavage  less  distinct  indicates  a 
right  oblique  prismy  deviating  3°  or  4°  from  right  angles. 

1.  When  ignited  it  becomes  brown  and  loses  2.7  per  cent  of 
its  weight.  ,  When  digested  in  muriatic  acid  it  gradually  dis- 
solves without  effervescence.  It  consists  of 

Silex,  29.64 

Protoxide  of  manganese,    66. 60 
Peroxide  of  iron,  0.92 

Moisture,  2.70 

It  hence  consists  of  1  atom  of  silica,  16-1-1  atom  of  protox- 
ide manganese  36.  It  has  been  known  as  the  rhomboidal  sili- 
cate of  zinc. 

It  is  found  at  Franklin,  N.  Y. 

23.  FERRO-SILICATE  OF  MANGANESE, 
Fowleriie. 

Colour  brown,  with  a  shade  of  red.  Lustre  dull,  ex- 
ternally, but  shining  and  splendent  internally,  and  pre- 
senting tints  of  red  and  gray.  Hardness  6.0.  Sp.  gr. 
3.44.  Thompson.  Cleavage  three-fold,  indicating  a  doubly 
oblique  prism  for  its,  primary  form. 


P  on  M  180°  00 
P  on  T  86  30 
MonT  86  30 


1.    When  treated  with  muriatic   acid  much  chlorine  is 
evolved,  becomes  white,  and  its  sp,  gr,  is  increased  to 


SPAR.  139 

This  mineral  was  constituted  originally  of  4  atoms  of  silicate 
of  manganese,  and  1  atom  of  per-silicate  of  iron. 

It  has  been  known  for  sometime  as  crystalized  siliceous 
oxide  of  manganese. 

24.  FERRUGINOUS  SILICATE  OF  MANGANESE. 
Colour  externally  brown,  with  a  slight  shade  of  red. 
Streak  flea-brown.  Lustre  externally  glimmering,  inter- 
nally shining  and  vitreous.  Fracture  foliated.  Cleavage 
indistinct.  Aspect  of  the  crystals  dodecahedrons,  but  their 
forms  are  too  imperfect  to  admit  of  a  correct  designation 
and  measurement ;  but  by  conjecture  the  inclination  of  the 
contiguous  planes  are  124°.  Hardness  2.0 — 2.5.  Sp. 
gr.  3.01, 

1.  It  dissolves  with  effervescence  in  muriatic  acid,  giving  out 
much  chlorine,  and  leaving  the  silica  undissolved.     By  analy- 
sis the  following  constituents  were  obtained  : 
Silex,  30.65 

Protoxide  of  manganese,    46.21 
Peroxide  of  iron,  15.45 

Loss  by  heat,  7.30 

The  atomic  constitution,  as  stated  by  Thompson,  is  3  at- 
oms of  silicate  of  manganese-j-1  atom  sesqui-per-silicate  of 
iron. 

This  mineral  was  considered  as  a  Silicate  of  Zinc,  until 
the  investigation  of  Prof.  Thompson  determined  its  true  com- 
position. 

It  occurs  at  Franklin  and  at  Stirling,  N.  J. 

25.  SESQUISILICATE  OF  MANGANESE. 

Colour  iron-black.  Streak  brown.  Lustre  vitreous. 
Powder  brown.  Brittle,  and  easily  reduced  to  powder. 
It  is  not  scratched  by  the  knife,  but  easily  by  quartz,  and 
with  some  difficulty  by  feldspar.  Not  magnetic.  Sp.  gr. 
3.67. 

1.  Its  constituents  are, 

Silex,  38.38 

Protoxide  of  manganese,  51.66 

Peroxide  of  iron,  9.44 


140  GEM. 

Its  atomic  constituent  is  stated  to  be  1 J  atom  silica+1  at- 
om protoxide  of  manganese. 

It  had  received  the  designation  of  granular  dysluite.  It  is 
associated  with  massive  yellow  garnet  and  franklinite.  It 
seems  to  belong  to  the  order  Ore,  in  the  natural  system,  but 
is  placed  now  in  connexion  with  the  other  manganesian  mine- 
rals. 

ORDER  VII.    GEM. 
GENUS  I.    ANDALUSITE. 

H.  =7.5 

G.  =-3.0—3.2 

1.    PRISMATIC  ANDALUSITE. 

Prismatic  J)ndalusite,  (first  sub-species.)    Jam. 
Andalusite.    Phil.     C. 

Colour  white,  reddish-white,  flesh-red,  and  sometimes 
purplish-red.  Streak  white.  Translucent.  Lustre  vit- 
reous. Brittle.  Structure  lamellar,  with  natural  joints 
parallel  to  the  side  of  a  rhombic  prism,  affording  by  meas- 
urement angles  of  91°  20'  and  88°  40'.  Hardness  7.5. 
Sp.  gr.  3.10.  Occurs  massive  with  a  composition  indis- 
tinctly granular. 

1.  Before  the  blow-pipe  it  is  infusible  ;  it  dissolves  with  dif- 
ficulty in  borax,  and  scarcely  at  all  in  salt  of  phosphorus. 

It  consists  of         Aluminej  60.5 

Silex,  36.5 

Oxide  of  iron,       4.0 

2.  Andalusite  is  found  imbedded  in  mica  slate  and  in  gran- 
ite.   This  species  was  first  discovered  in  Andalusia  in  Spain. 
In  the  United  States  it  is  found  at  Litchfield,  Ct.  and  at  Lan- 
caster and  Westford,  Mass,  in  crystals  of  various  shades  of 
red,  yellow  and  brown,  associated  with  rhsctizite  and  a  fibrous 
substance  resembling  Buchohite.    The  andalusite  of  the  last 
mentioned  localities  resembles  that  from  the  Sualpi  in  Carin- 
thia. 


GEM.  141 

GENUS  II.    CORUNDUM. 

H.  =8.0—9.0 
G.  =3.5—4.3 

1.  DODECAHEDRAL  CORUNDUM. 
Octahedral  Corundum.  (2d  and  3d  sub-species.)    Jam. 
Pleonaste-Spinelle.    Ruby.    Phil. 

Colour  red,  passing  into  blue  and  green,  also  yellow, 
brown  and  black,  sometimes  nearly  white.  Streak  white. 
Transparent... translucent  only  on  the  edges,  if  the  colour 
is  dark.  Lustre  vitreous.  Fracture  conchoidal.  Cleav- 
age difficult,  parallel  to  the  planes  of  an  octahedron. 
Hardness  8.0.  Sp.  gr.  3.52. 

i.  2.  3. 


Fig.  1.  The  regular  octahedron,  which  is  the  primary  form.  Fig. 
2.  Edges  of  the  octahedron  replaced.  Fig.  3.  Rhombic  dodecahe- 
dron. 

1.  Before  the  blow-pipe  with  borax  this  mineral  fuses  with 
difficulty,'  yielding  a  deep  green  enamel. 

Included  in  this  species  are  three  varieties,  viz  :  Blue  Spi- 
nelle, Red  Spi?iette  and  Pleonaste.  They  consist  of  the  fol- 
lowing elements  : 

Blue  Spinelle.        Red  Spindle.        Pleonaste. 
Alumina,  72.25  74.50  68.00 

Silica,  5.45  15.50  2.00 

Magnesia,  14.63  8.25  12.00 

Oxide  of  iron,        4.26  1.50  16.00 

Berzelius.        Klaprotli*       Descotils. 
Vauquelin  discovered  6.11  per  cent  of  chromic  acid  in  the 
red  spinelle. 

2.  Fine  specimens  of  Pleonaste  and  Spinelle  have  been  found 
at  Warwick,  N.  Y.  of  extraordinary  dimensions,  varying  from 
one  to  sixteen  inches  round  the  base.     Colours  black,  grayish- 
bJack,  bluish-black  and  reddish-brown  and  green.     It  is  also 
found  at  Haddam,  Ct.  and  Chelmsford,  Mass. ;  at  the  latter 


142  GEM. 

place  of  a  beautiful  sky-blue.  The  Spinel le  of  Orange  and 
Sussex  counties,  though  at  present  not  abundant,  is  found  in 
irregular  veins  in  a  coarse  crystaline  limestone,  associated  with 
hornblende,  mica,  bronzite  and  Brucite. 

2.  OCTAHEDRAL  CORUNDUM. 

Octahedral  Corundum,  (first  sub-species.)    Jam. 
Automalite.    Phil.    C. 

Colour  dirty  green,  inclining  to  black  and  blue.    Streak 
rhite.     Translucent  on  the  edges.. .opake.     Lustre  vitre- 
ous, inclining  to  resinous.     Hardness  8.0.  Sp.  gr.  4.23. 
Cleavage  parallel  to  the  planes  of  a  regular  octahedron. 

1.  Alone  it  is  infusible,  and  nearly  so  with  borax  or  salt  of 
phosphorus.     With  soda  it  fuses  into  a  dark  scoria,  which  on 
being  melted  again  with  soda,  deposits  an  areola  of  oxide  of 
zinc.     It  consists  of 

Alumina,  60.00 

Oxide  of  zinc,  24.25 
Oxide  of  iron,  9.25 
Silica,  4.75 

2.  Automalite  is  found  at  Franklin,  N.  J.  and  at  several 
places  in  the  neighborhood.     It  is  now  a  rare  mineral. 

3.  RHOMBOHEDRAL  CORUNDUM. 

Rhomboidal  Corundum.    Jam. 
Corundum.    Phil.    C. 

Colour  blue,  red,  green,  yellow,  brown,  gray  and 
white.  Streak  white.  Transparent.. .translucent.  Lus- 
tre vitreous.  It  possesses  double  refraction.  Several 
varieties,  when  cut  round,  exhibit  a  six-sided  opalescent 
star  in  the  direction  of  the  axis.  Hardness  9.0.  Sp.  gr. 
3.92 — 3.97.  It  yields  to  mechanical  division  easily  in 
one  direction  with  a  perfect  brilliant  surface.  Primary 
form  a  slightly  acute  rhomboid,  affording  angles  of  86°  4' 
and  93°  56'. 

The  massive  compound  varieties  are  granular,  general- 
ly fine  and  passing  into  impalpable. 


GEM.  143 

1.  Corundum  is  the  name  given  to  the  common  form  of  this 
mineral  by  the  inhabitants  of  India.     When  crystalized  and 
pure,  it  is  called  Sapphire  ;  when  the  colour  is  red,  it  is  call- 
ed Oriental  Ruby.    The  compound  variety  is  known  as  the 
Emery. 

2.  Before  the  blow-pipe  it  suffers  no  change  even  in  the 
form  of  powder.     It  dissolves  slowly  but  perfectly  in  borax. 
Acids  have  no  effect  upon  it.     The  following  varieties  furnish 
the  following  results  by  analysis  : 

Sapphire.     Corundum  Stone,       Emery. 
Alumina,  98.50  89.50  86.00 

Silica,  0.00  5.50  3.00 

Oxide  of  iron,       1.00  1.25  4.00 

Lime,  0.50  0.00  0.00 

Klaproth.        Klaproth.         Tennant. 

3.  Rhombohedral  corundum  is  found  in  crystals  imbedded 
in  the  massive  varieties.     The  most  perfect  of  the  species,  as 
the  sapphire  and  oriental  ruby,  are  met  with  principally  in 
secondary  deposites,  as  the  sand  of  rivers,  &c. 

The  finest  varieties  are  from  Pegu.  In  St.  Gothard,  red 
and  blue  varieties  occur  in  dolomite.  Emery  is  found  in  Saxo- 
ny and  in  the  Island  of  Nazos,  in  the  Grecian  Archipela- 
go. 

4.  There  are  a  few  localities  of  Sapphire  in  the  United  States, 
viz  :  Newton,  in  the  county  of  Sussex,  N.  J.    It  is  there  found 
imbedded  along  with  a  white  feldspar  in  limestone,  near  the 
junction  of  the  granitic  sienite  and  the  white  granular  lime- 
stone.    It  is  blue  and  white,  the  central  part  of  a  bright  ber- 
lin-blue,  becoming  pale  towards  the  surface.     It  is  associated 
with  pleonaste,  red  oxide  of  titanium,  yellowish-green  idocrase, 
condrodite  and  pyramidal  feldspar.     Other  localities  will  pro- 
bably be  discovered  by  tracing  the  direction  of  the  veins  north 
and  south,  as  the  deposites  of  all  those  rare  and  interesting 
minerals  in  the  counties  of  Orange  and  Sussex,  have  at  least 
some  degree  of  regularity,  or  are  not  to  be  found  very  far  east 
or  west  of  a  given  line. 

5.  The  pure  and  transparent  varieties  of  Octahedral  corun- 
dum are  highly  esteemed  as  ornamental  stones.     The  red  are 
most  highly  valued,  and  go  by  the  name  of  oriental  Ruby  ;  the 
violet  blue  are  called  oriental  JJmethyst  ;  the  green,  oriental 
Emerald ;  the  yellow,  oriental  Topaz,  and  the  blue  oriental 
Sapphire. 

Corundum  is  much  used  for  cutting  and  polishing  steel  and 
gems,  and  it  is  also  said  even  the  diamond. 


144 


GEiM. 


4.  PRISMATIC  CORUNDUM. 

Prismatic  Corundum,  or  Crysoberyl.    Jam. 
Crysoberyl.    Phil.     C. 

Colour  asparagus- green,  passing  into  greenish- white, 
olive-green  and  yellowish-gray.  Streak  white.  Trans- 
parent.... translucent.  Lustre  vitreous.  Occasionally 
there  appears  in  the  interior  an  opalescing  bluish-white 
light,  if  viewed  in  the  direction  perpendicular  to  the 
shorter  diagonal  of  the  primary  form.  Fracture  con- 
choidal.  ,  Hardness  8.5.  Sp.  gr.  3.75.  Primary  form  a 
right  rectangular  prism.  It  yields  to  cleavage  parallel  to 
the  plane  M.  M  on  T  90°  OCX. 


r 

\ 

t 

X  p  x 

"X    tf" 

M  on  T    90° 

M 

«/ 

M 

T 

Mon  i    90 
M  on   s  125    16' 

>X  T  on   i  120 

X         T  on  s  144    44 

^lf*~ 

x.. 

Troost.    Jour.  Science,  vol.  iii.  p.  294. 

\ 

\ 

T 


1.  Before  the  blow-pipe  it  remains  unchanged, 
rax  it  fuses  with  difficulty.     It  consists  of 

Brazil. 

Alumine,  68.66 

Glucina, 

Silex, 

Protoxide  of  iron, 

Oxide  of  titanium 

Moisture, 


With  bo- 


16.00 
5.99 
4.73 
2.66 
0.66 


Haddam. 

73.60 

15.80 

4.00 

3.38 

1.00 

0.40  Seybert. 


2.  Prismatic  Corundum  occurs  at  Haddam,  Ct.,  and  at 
Saratoga,  N.  Y.,  in  granite. 


GEM*  145 

GENUS  HI.    DIAMOND. 

H.=10.0 
G.=3.4.— 3.6 

1.  OCTAHEDRAL  DIAMOND. 

Octahedral,  or  Common  Diamond.    Jam. 
Diamond.    Phil.     C. 

Colour  white,  prevalent.  Also  various  shades  of  blue, 
red,  yellow,  green,  brown,  gray,  and  even  black  :  colours 
generally  pale.  Streak  white.  Transparent.. .translu- 
cent. If  cut  and  polished  it  exhibits  a  lively  play  of 
light.  Hardness  10.0.  Sp.  gr.  3.52.  Cleavage  per- 
fect, parallel  to  the  planes  of  the  regular  octahedron. 

123  45 


Fig.  1.  The  primary,  the  regular  octahedral.  Fig.  2.  Octahedron, 
with  the  solid  anglesTeplaced.  In  Fig.  3,  those  planes  are  complete. 
Fig.  4.  The  edges  of  the  octahedron  replaced  by  six-sided  planes.  In 
Fig.  6,  those  planes  are  complete. 

1.  Octahedral  Diamond  is  perfectly  combustible  at  the  tem- 
perature of  about  14°  of  Wedgewood's  pyrometer,  and  yields 
with  oxygen,  carbonic  acid  gas.    Acids  and  alkalies  have  no 
effect  upon  it.     It  consists  of  carbon  in  its  purest  form. 

2.  The  Diamond  has  been  found  in  secondary  deposits,  in 
a  district  which  abounds  with  debris  of  sandstone  rock,  which 
are  often  aggregated  or  cemented  together  into  a  sort  of  coarse 
breccia.     It  occurs  likewise  in  the  loose  sand  of  plains  and 
rivers. 

3.  The  diamond  was  first  discovered  in  the  East  Indies.     It 
is  likewise  found  in  Brazil,  in  the  district  of  Serro  do  Frio, 
and  in  the  Ural  chain  of  mountains,  in  the  neighborhood  of 
Koushra,  and  at  Nigny-Toura,  Russia. 

4.  This  mineral  is  the  most  valued  of  all  gems  ;  it  is  used 
as  an  ornamental  stone,  and  obtains  a  preference  above  all 
others.     For  cutting  glass,  and  for  engraving,  cutting  and 
polishing  other  hard  stones,  it  is  indispensable. 

13 


146  GEM. 

GENUS  IV.    TOPAZ. 

H.=8.0 

G.==3.4— 3.6 

3.  PRISMATIC  TOPAZ. 

Prismatic  Topaz.    Jam. 
Topaz.     Phil.     C. 

Colour  various  shades  of  yellow,  green  and  blue;  like- 
wise white ;  colours  generally  pale.  Streak  white. 
Transparent... translucent.  Lustre  vitreous.  Hardness 
8.0.  Sp.  gr..  3.49.  Cleavage  distinct  and  perfect  at 
right  angles  to  the  axis,  and  difficult  parallel  to  the  late- 
ral planes  of  a  right  rhombic  prism,  which  is  the  primary 
form.  M  on  M'<  124°  22'.  P  on  M  or  M'  90°  OCH. 
Hauy. 

1.  Before  the  blow-pipe  Topaz  is  infusible ;  with  borax  it 
fuses  slowly  into  a  transparent  glass.     Berzelius  considers 
the  Topaz  as  a  compound  of  1  atom  of  sub-fluate  of  alumina+ 
3  atoms  of  silicate  of  alumina.     This  corresponds  nearly  to 
silex  24,  alumina  57.45,  fluoric  acid  7.75.     The  Physalite  and 
Pycnite  vary  but  little  in  composition  from  the  above. 

2.  The  Topaz  belongs  almost  exclusively  to  primitive  coun- 
tries, and  even  enters  into  the  composition  of  some  granitic 
rocks.     The  Pycnite  is  a  compound  variety,  consisting  of  in- 
dividuals closely  joined  in  composition,  and  deeply  streaked 
longitudinally.    It  never  possesses  bright  colours,  or  a  high  de- 
gree of  transparency.     Physalite  is  a  still  more  imperfect  va- 
riety of  Topaz.     It  occurs  usually  in  large  massive  individu- 
als, whose  colours  are  usually  pale  greenish-gray. 

3.  The  most  perfect  crystals  of  topaz  come  from  Siberia. 
They  are  usually  green,  blue  or  white.     They  are  associated 
with  rhombohedral  Emerald.      Those  from  Brazil  are  met 
with  in  loose  pebbles  of  high  yellow  colours.     The  Mexican 
Topaz  is  white  or  limpid. 

Prismatic  Topaz,  when  its  colours  are  bright,  is  used  as  an 
ornamental  stone,  but  is  less. valued  than  the  sapphire.  It  is 
found  inMunroe,  Ct.,  of  a  very  great  size,  though  not  perfect  in 
form ;  also  on  the  Amonoosuck,  near  the  falls,  in  the  White 
Mountains,  N.  H.  The  former  locality  is  probably  exhaust- 
ed ;  the  latter  has  furnished  but  few  specimens,  but  deserves 
farther  examination. 


GEM.  147 

GENUS  V.    EMERALD. 

H.=7.5— 8.0 
G.=2.6— 3.2 

1.  PRISMATIC  EMERALD. 

Prismatic  Emerald)  or  Euclase.    Jam. 
Euclase.    Phil.     C. 

Colour  green,  passing  into  blue  and  white,  and  always 
pale.  Streak  white.  Transparent. ..translucent.  Lus- 
tre vitreous.  Very  brittle  and  fragile,  from  which  pro- 
perty the  name  Euclase  has  been  derived.  Mohs.  Hard- 
ness 7.5.  Sp.  gr.  3.09.  Cleavage  perfect,  parallel  to  P, 
less  so  in  the  direction  M  and  Z,  of  a  right  oblique  angled 
prism,  which  is  considered  as  the  primary  form. 

1.  Before  the  bjow-pipe  it  intumesces  in  a  strong  heat,  and 
becomes  white,  and  finally  melts  into  a  white  enamel. 

It  consists  of         Silica,  43.22 

Alumina,  30.56 

-      Glucina,  21.78 

Oxide  of  iron,  2.22 

Oxide  of  tin,  0.70    Berzelius. 

2.  It  is  yet  a  scarce  mineral.     It  was  first  brought  to  Eu- 
rope from  Peru.    It  occurs  in  a  chloritic  slate,  resting,  it  is 
said,  on  sandstone. 

2.  RHOMBOHEDRAL  EMERALD. 

Rhomboidal  Emerald.    Jam. 

Beryl.    Aquamarine  Emerald.     Phil.     C. 

Colour  green,  passing  into  blue,  yellow  and  white ; 
the  brightest  green  is  termed  emerald-green ;  the  colours 
are  generally  pale,  and  unequally  diffused  through  the 
specimens.  Streak  white.  Lustre  vitreous.  Hardness 
7.5—8.0.  Sp,  gr.  2.67—2.73. 

1.  In  a  strong  heat  before  the  blow-pipe  the  edges  of  the 
fragments  are  rounded ;  in  borax  it  dissolves  slowly. 

The  two  varieties  included  in  this  species,  Emerald  and 
Beryl,  differ  only  in  colour:  in  the  Emerald  it  is  a  bright  and 


148  GEM. 

peculiar  green ;  the  Beryl  is  yellow  or  duH  yellowish-green, 
with  surfaces  more  or  less  rough,  and  striated  transversely. 
They  consist  of       Silex,  68.35 

Alumina,  17.60 
Glucina,  13.13 
Oxide  of  iron,  0.72 

2.  The  finest  specimens  of  Emerald  are  brought  from  Peru. 
They  are  in  druses  in  a  limestone  rock,  and  likewise  in  horn- 
blende, day-slate  and  granite.  The  beryls  in  this  country  oc- 
cur in  granite  or  mica  slate,  and  most  of  our  primitive  sec- 
tions of  country  furnish  them.  In  Ackworth,  N.  H.,  they 
are  very  large,  but  not  of  fine  colours. 

GENUS  VI.    QUARTZ. 

H  =5.5—7.5 
G.  =1.9— 2.7 

1.  PRISMATIC  QUARTZ. 

Tolite.    Jam.    Mile.    Dichroite.    Phil. 

Colour  various  shades  of  blue,  generally  inclining  to 
black.  Streak  white.  Transparent... translucent.  Lus- 
tre vitreous.  When  viewed  in  the  direction  of  the  axis 
the  crystal  appears  blue,  and  yellowish-gray  perpendicu- 
lar to  it.  Hardness  7.0 — 7.5.  '  Sp.  gr.  2.58.  It  is  said 
to  possess  natural  joints,  parallel  to  the  planes  of  a  six- 
sided  prism.  Occurs  crystalized  in  six  and  twelve-sided 
prisms. 

Compound  varieties  are  massive,  and  hard  to  be  distin- 
guished. Composition  granular,  and  strongly  adherent. 

1.  Before  the  blow-pipe  it  melts  with  a  high  heat  on  the 
edges  only,  into  a  glass  near  the  colour  of  the  mineral. 

lolite  and  Peliom  scarcely  differ  sufficiently  to  form  varie- 
ties. The  former  was  discovered  at  Cabo  de  Gata,  in  Spain, 
the  latter  at  Bodenmais,  in  Bavaria,  both  massive  and  crys- 
talized, associated  with  rhombohedral  quartz,  garnet,  &c.  It 
furnishes  by  analysis, 

Silica,  48.53 

Alumina,  31.73 

Magnesia,  11.30 

Oxide  of  iron,  5.68 


GEM. 


149 


Oxide  of  manganese,      0.70 
Water  and  loss,  1.64 

It  is  said  to  occur  at  Goshen,  Mass.,  in  granite. 

2.  RHOMBOHEDRAL  QUARTZ. 

Rhomboidal  Quartz,  (excepting  Porcelain  Jasper.)  Jam.  Quarts, 
(exc.  Hyalite.)  Cals-eye  Flint.  Chalcedony,  (exc.  Cacholong.) 
Jasper,  (exc.  Porcelain  Jasper.)  Hornstone.  Phil. 

Prevailing  colour  of  the  species  white;  other  distin- 
guishing colours  are  violet-blue,  rose-red,  clove-brown, 
and  apple-green,  each  of  which  form  a  variety.  Dark- 
brown  and  green  colours  are  owing  generally  to  foreign 
admixtures.  Streak  white.  Transparent... translucent. 
Opake  when  impure.  Cleavage  very  difficult  and  indis- 
tinct. Primary  form  a  rhomboid  of  94°  15'  and  85°  45'. 
Hardness  7.0.  Sp.  gr.  2.69. 


P  on  r  141°  40' 

Zonr  141    40 

P  &  Z  on  o  128    20 
r  on  r  120 


Fig.  1.  Primary  form.  Fig.  2.  Quarts  annulaire,  formed  by  the 
decrement  of  one  row  of  molecules  parallel  to  the  summit  of  the 
ihomboid. 

Compound  varieties  numerous.  Thus  it  occurs  in 
globular,  reniform  and  stalactitic  shapes.  Also  in  colum- 
nar, of  a  usually  coarse  structure,  and  in  laminated  and 

13* 


150  GEM. 

granular  masses — the  latter  passing  into  impalpable. 
Sometimes  it  occurs  in  pseudo-morphous  crystals,  which 
are  hexahedrons  and  octahedrons.  It  sometimes,  though 
rarely,  occurs  in  ovoidal  or  globular  masses,  somewhat 
resembling  fused  globules  of  glass.  The  forms  mentioned 
in  this  paragraph  usually  constitute  varieties  which  re- 
ceive particular  descriptions  in  books  on  Mineralogy. 

The  most  important  sub-species  are  the  following :  1. 
Amethyst^  which  is  of  a  violet-blue  colour,  and  of  a  coarse 
fibrous  structure.  2.  Rock  Crystal,  which  is  limpid  and 
transparent,  or  semi-transparent,  together  with  the  white 
massive  varieties.  3.  Rose  Quartz,  which  is  massive, 
and  of  a  rose-red  colour.  4.  Prase,  which  is  a  dark  leek- 
green;  and,  5.  Common  Quartz,  which  includes  the 
massive,  laminated  and  granular  varieties. 

1.  The  Common  Quartz  passes  insensibly  into  the  other 
varieties,  such  as  Hornstone,  which  is  translucent,  and  ex- 
hibits a  dull,  splintery  fracture.  Hornstone  seems  very  near- 
ly allied  to  Flinty  Slate,  Lydian  Stone,  Jasper  and  Helio- 
trope. Flinty  Slate  is  divided  into  many  angular  masses  by 
seams,  but  as  a  whole  it  is  slaty.  Lydian  stone  forms  masses 
in  flinty  slate,  free  from  seams,  and  presents  a  large  conchoidal 
fracture,  and  a  perfectly  compact  structure.  Jasper  has  a 
composition  which  is  impalpable,  with  a  large  conchoidal  frac- 
ture, but  generally  coloured  red  by  the  peroxide  of  iron ;  it 
occurs,  however,  of  all  colours,  and  the  darker  ones  resemble 
Lydian  stone.  Heliotrope  is  a  variety  of  common  quartz, 
coloured  by  green  earth,  but  containing  blood-red  spots  of 
Jasper.  The  coarser  kinds  are  found  in  masses  in  Flinty 
Slate.  Those  stalajctitic  and  botryoidal  forms  of  common 
quartz  which  are  deposited  in  layers,  with  surfaces  rough  or 
drusy,  constitute  Chalcedony.  Colours  usually  milk-white, 
when  they  are  red  or  reddish,  are  distinguished  as  Carne- 
lian.  Chrysoprase  is  also  a  variety  of  chalcedony,  coloured 
green  by  the  oxide  of  nickel.  Plasma,  another  variety  of 
chalcedony,  is  coloured  leek-green,  and  sometimes  grass- 
green,  by  some  substance  not  yet  well  determined.  Catseye 
is  a  variety  of  fibrous  quartz,,  of  a  greenish-gray,  and  which 
exhibits  a  peculiar,  coalescence  when  cut  into  a  convex  sur- 


OEM.  151 

face  and  polished.  Hyacinth  from  Compostetta,  is  produced 
by  a  large  admixture  of  oxide  of  iron.  The  individuals  are 
opake,  but  present  the  regular  hexahedral  prism,  terminated 
by  pyramids  at  each  extremity,  and  very  rarely  modified  by 
replacement.  The  intermixture  of  oxide  of  iron  produces  a 
passage  of  quartz  into  iron  flint,  or  flinty  iron  ore. 

2.  Quartz  is  infusible   before  the  blow-pipe.     The  most 
perfect   varieties  are  nearly  pure  silex.    Bucholz  obtained 
99.37  parts  of  silex  from  rock  crystal. 

3.  Silex  is  one  of  the  most  common  substances  in  nature. 
It  enters  into  the  composition  of  rocks,  and  is  very  widely 
distributed.    It  is  spread  all  over  the  globe. 

3.  UNCLEAVABLE  QUARTZ. 

Indivisible  Quartz.    Jam. 

Hyalite.     Opal.     Hydrophane.     Menilite.     Cacholong.    Siliceous 
Sinter.    Phil.    C. 

Colour  white,  yellow3  red,  brown,  green,  gray.  The 
lively  colours  are  the  red  and  green  ones ;  the  others  are 
pale.  The  dark  colours  are  owing  to  foreign  admixture. 
Streak  white.  Lustre  vitreous,  inclining  to  resinous. 
Fracture  conchoidal.  Transparent... translucent ;  some- 
times only  on  the  edges.  Occasionally  some  specimens 
exhibit  a  lively  play  of  light  in  the  interior ;  others  show 
different  colours  by  reflected  and  refracted  light.  Hard- 
ness 5.5—6.5.  Sp.  gr.  2.9. 

Compound  varieties. — Small  reniform,  botryoidal  and 
stalactitic  shapes,  and  large  tuberose  concretions.  In  the 
former  the  surface  is  smooth,  in  the  latter  rough.  Com- 
position impalpable.  Fracture  conchoidal,  even. 

1.  The  following  varieties  under  uncleavable  quartz  com- 
prehend the  most  important :  1.  Opal  It  is  subdivided  into 
precious,  common,  semi-opal  and  wood  opal.  Precious  opal, 
when  cut  and  polished  into  a  convex  surface,  exhibits  in  the 
interior  a  play  of  light  which  often  preserves  constant  direc- 
tions* within  single  parts  of  the  mass.  This  play  of  light  is 
supposed  to  be  connected  with  a  regular  structure.  Common 
and  semi-opal  differ  from  the  precious  by  having  an  inferior 
degree  of  lustre  and  transparency.  Wood  opal  appears  in  the 


152  GEM* 

form  of  trunks,  roots  and  branches  of  trees.  2.  Hydrophane 
is  a  variety  of  opal  which  is  naturally  opake,  but  becomes 
translucent  by  immersion  in  water.  3.  Hyalite  occurs  in 
small  reniform,  botryoidal  and  sometimes  stalactitic  shapes, 
with  generally  a  considerable  degree  of  transparency.  It  re- 
sembles in  colour  and  lustre  gum  arable.  4.  Menilite  oc- 
curs in  tuberose  forms,  but  is  opake.  It  is  subdivided  into 
brown  and  gray  Menilite.  5.  Siliceous  sinter  is  a  deposit  of 
silex  from  hot  springs. 

2.  Uncleavable  quartz  consists  of 

Precious  Opal.    Hyalite.      Menilite. 
Silex,       92.00  90.00       85.50 

Water,       6.33  10.00       11.00 

3.  It  usually  forms  short  irregular  veins,  strongly  connected 
with  the  matrix,  in  porphyry  and  amygdaloid.     It  occurs  more 
abundantly  in  Hungary  than  any  other  country. 

Precious  opal  is  considered  as  a  gem,  and  is  generally  cut 
with  a  convex  surface.  If  the  specimens  are  large  and  pure, 
and  possess  vivid  colours,  they  are  of  considerable  value. 

4.  EMPYRODOX*  QUARTZ. 
Pearlstone.     Pitchstone.    Pumice.     Obsidian.    Phil.    C. 

Colours  black,  brown,  red,  yellow,  green,  gray,  white, 
dull.  Streak  white.  Faintly  transparent... translucent 
on  the  edges.  Lustre  vitreous,  and  resinous.  Cleavage 
none.  Fracture  conchoidal,  perfect,  uneven.  Hardness 
6.0—7.0.  Sp.  gr.  2.39—2.21. 

1.  The  following  varieties  are  included  in  empyrodoz 
quartz :  1.  Obsidian,  usually  opake,  and  sometimes  transpa- 
rent. Fracture  large"  conchoidal.  Lustre  purely  vitreous, 
in  perfect  forms.  When  the  conchoidal  fracture  is  lost,  and 
the  lustre  becomes  resinous,  it  passes  into  Pitchstone.  2. 
Pearlstone  is  formed  of  concretions,  more  or  less  rounded, 
and  which  may  be  separated  from  the  mass,  and  likewise  in 
thin  films,  which  are  partially  concentric:  they  sometimes 
contain  a  grain  of  Obsidian.  3.  Pumice  occurs  in  fibrous,  vesic- 
ular masses,  often  extremely  light  and  porous,  and  of  a  gray 
colour,  These  varieties  are  often  connected  in  the  same  spe- 
cimen. 

2.  They  consist  as  follows :  ^ 

*  From  empuros,  belonging  to  fire,  and  doxa,  the  opinion. 


GEM.  153 


Obsidian. 

Pitckstonc.  • 

Pearlstonc, 

Pumice, 

Silex, 

72.00 

73.00 

75.25 

27.50 

Alumina, 

12.50 

14.56 

12.00 

17.50 

Potash,  and  ? 
soda,        5 

10.00 

0.00 
1.75 

4.50 
0.00 

3.00 

Oxides  of  iron  and  > 

2.00 

1.10 

1.60 

1.75 

manganese,        J 

Lime, 

0.00 

1.00 

0.50 

0.00 

Water, 

0.09 

8.50 

4.50 

0.00 

3.  The  above  varieties  belong  exclusively  to  volcanic  moun- 
tains. 

Obsidian  is  sometimes  used  for  mirrors,  vases,  snuff-boxes, 
&c.  Pumice  is  a  well  known  material,  and  is  useful  for  grind- 
ing and  polishing. 

GENUS  VII.    AXINITE. 

H.=6.5— 7.0 
G.  =3.0—3.3 

1.  PRISMATIC  AXINITE, 
Prismatic  Axinite.    Jam.    Axinitt.    Phil.    C. 

Colour  usually  clove-brown,  sometimes  passes  into 
plum-blue  or  pearl  gray,  and  when  mixed  with  chlorite, 
green.  Streak  white.  Transparent... translucent.  Hard- 
ness 6.5 — 7.0.  Sp.  gr.  3.27.  Primary  form  undeter- 
mined. Cleavage  irregular.  General  form  of  the  crys- 
tals a  doubly  oblique  prism.  P  on  M  134°  40'.  P  on  T 
115°  17'.  MonT  135°  10'. 

Compound  varieties.  Composition  lamellar,  passing 
into  granular,  and  even  impalpable. 

1.  Before  the  blow-pipe  it  fuses  easily  into  a  dark-green 
glass.  It  consists  of 

Silex,  50.50 

Lime,  17.00 

Alumine,  16.00                               . 

Oxide  of  iron,  9.50 

"    manganese,  5.25 

Potash,  0.25    Klaproth. 


154  GEM. 

2.  Prismatic  axinite  occurs  in  veins  in  primitive  rocks.  It 
is  found  at  Thum  in  Saxony,  hence  the  name  Thumerstone  or 
Thumite. 

GENUS  VIII.    CHRYSOLITE. 

H— 6.5—7.0 
G.=2.8— 3.0 

1.  PRISMATIC  CHRYSOLITE. 

Prismatic  Chrysolite.    Jam. 
Chrysolite.     Olivine.    Phil.    C. 

Colour  various  shades  of  green,  as  pistachio-olive,  as- 
paragus-green and  grass-green,  and  sometimes  passing 
into  brown.  Streak  white.  Transparent... translucent. 
Lustre  vitreous.  Fracture  conchoidal.  Hardness  6.5 — 
7.0.  Sp.  gr.  3.44.  Primary  form  a  right  rectangular 
prism,  which  may  be  obtained  by  cleavage,  parallel  to  all 
its  planes. 

Compound  varieties.  They  are  principally  irregular 
spheroidal  masses,  imbedded  in  rocks.  Composition  granu- 
lar individuals  easily  separated. 

1.  Before  the  blow-pipe  chrysolite  becomes  darker,  but  does 
not  melt.     Olivine  loses  its  colour  in  heated  nitric  acid.    Pris- 
matic chrysolite  and  oli vine,  though  they  differ  somewhat  in 
chemical  composition,  yet  they  by  no  means  differ  in  their  es- 
sential characters.     Chrysolite  is  crystalized  and  possesses 
bright  colours,  while  Olivine  is  a  compound  variety  and  pos- 
sesses inferior  colours  and  less  transparency.    Their  constitu- 
ent elements  are  as  follows  : 

Chrysolite.  Olivine. 

Silex,                        39.00  ,  50.00 

Magnesia,                 43.50  38.50 

Oxide  of  iron,            19.00  12.00 

Lime,                          0.00  0.25 

2.  The  original  repository  of  chrysolite  is  unknown.    Im- 
perfect varieties  are  found  imbedded  in  lava,  and  come  from 
the  neighborhood  of  volcanoes. 


GEM.  155 

V  '•-/ 

GENUS  IX.    BORACITE. 

H.=7.0 
G.=2.8— 3.0 

1.  TETRAHEDRAL  BORACITE. 

Hexahedral  Boracite.    Jam. 

Boracite.    Borate  of  Magnesia.    Phil.    C. 

Colour  white  or  grayish- white,  -  sometimes  inclining  to 
green  or  yellow.  Streak  white.  Semi-transparent... 
translucent.  Lustre  vitreous,  inclining  to  adamantine. 
Hardness  7.0.  Sp.  gr.  2.97.  Fracture  conchoidal,  un- 
even. Primary  form  a  cube.  The  general  form  of  the 
crystals  cubical. 

1.  Before  the  blow-pipe  upon  charcoal  it  intumesces  and 
melts  into  a  glassy  globule,  which  becomes  opake  and  white 
on  cooling.    It  consists  of 

Boracic  acid,  54.55 

,       Magnesia,  30.68 

Oxide  of  iron,  9.57 

.  Silex,  2.27 

It  is  a  bi-borate  of  magnesia. 

2.  Tetrahedral  Boracite  is  found  only  at  Liineburg  in  Bruns- 
wick and  Segeberg  in  Holstein,  imbedded  in  prismatic  Gyp- 
sum-haloide. 

GENUS  X.    TOURMALINE. 

H.=7.0--7.5 
G.=3.0— 3.2 

1.  RHOMBOHEDRAL  TOURMALINE. 

Rhomboidal  Tourmaline.     Jam. 
Tourmaline.     Phil.     C. 

,  Colour  brown,  green,  blue,  red,  white  and  black,  gen- 
erally dark,  but  rarely  bright.  Lighter  colours  transpar- 
ent...translucent  ;  dark,  opake.  Transparency  less,  if 
viewed  in  the  direction  of  the  axis  than  perpendicular  to 
it,  and  generally  the  colour  also  varies.  Lustre  vitreous. 
Streak  white.  Fracture  imperfectly  conchoidal,  uneven. 
Brittle.  Hardness  7.0—7.5.  Sp.  gr.  3.07.  Cleavage 


156 


GEM, 


very  difficult.     Primary  form  a  rhomboid  of  133°  50'  and 
46°  10'.     Electric  by  heat. 

Compound  varieties. — Rarely  granular,  generally  co- 
lumnar, parallel  or  divergent.  Crystals  often  deeply  fur- 
rowed longitudinally  and  traversed  by  seams  transversely, 
which  are  often  filled  with  quartz. 


PonP 

133°  50' 

P  or  P'  on  m 

156    60 

^^      PorP'ong 

141    10 

P 

P  on  i  or 

P'on  i 

138      7 

rt^t 

P  or  P'  on  e 

117    25 

e  on  e'  ore'' 

120    00 

e  on  f  1 

149    30 

{    e 

,f  1  onf2 

155    25 

1  2 

e  on  i  ori 

147    32 

eong 

136    15 

a  on  e 

90    00 

m  one 

103    30 

Phillips. 

1.  Tourmaline  is  the  name  appropriated  to  all  those  varie- 
ties of  this  species  which  are  not  black.     The  term  Schorl  de- 
notes the  common  black  variety.     Other  varieties  are  desig- 
nated by  particular  names.     Thus  ruMlite  is  a  red  variety  and 
indicolite  is  an  indigo-blue  variety,   possessing  however  tints 
of  various  hues.     Besides  these  there  are  green,  wUte  and 
brown  tourmalines. 

2.  Before  the  blow-pipe  Schorl  melts  easily  with  intumes- 
cence, the  green  and  blue  varieties  do  not  melt  so  easily  as 
black.     The  red  is  infusible.     They  consist  of 

Red,  Green,      Blue  &-  Black  Tourmaline. 

Silex,  42.00        40.00 

Alumine,  46.00        39.00 

Soda,  10.00          0.00 

Lithia,  0.00          0.00 

Potash,  0.00          0.00 

Lime,  0.00          3.84 

Oxide  of  iron,         0.00        1250 
do  manganese,     7.00          2.00 

Boracicacid,         0.00          0.00 

Water,  0.00          0.00 

Vauquelin.   Vauquelin.  Arfvedson.  Klaproth. 

31  Tourmaline  belongs  to  primitive  rocks  or  granite  and 
mica  slate.  The  brown  or  yellowish  brown  tourmaline  is  found 
in  dolomite. 


40.30 

36.75 

40.50 

34.50 

0.00 

0.00 

4.30 

0.00 

0.00 

6.00 

0,00 

0.00 

4.55 

21.00 

1.50 

0.00 

1.10 

0.00 

3.60 

0.00 

GEM-  157 

4.  The  green,  red  and  blue  varieties  are  found  in  Chester- 
field, Mass,  and  the  blue  in  very  large  crystals  in  Chester,  in 
a  coarse  grained  granite. 

5.  Tourmaline  when  free  from  flaws  and  of  a  good  colour, 
is  used  as  a  gem. 

^ENUS  XL    GARNET/ 

H=6.0— 7.5 . 
G=3.1— 4.3 

1.  PYRAMIDAL  GARNET. 

Pyramidal  Garnet,  (excepting  Gehlenite.)     Jam. 
Idocrase.     Phil,     C. 

Colour  various  shades  of  brown,  passing  into  leek- 
green,  pistachio-green,  olive  and  oil-green.  Streak  white. 
Semi- transparent... faintly  translucent  on  the  edges.  When 
viewed  in  the  direction  of  the  axis  the  colours  incline  to 
yellow  ;  perpendicular  to  it,  to  green.  Lustre  vitreous. 
Fracture  imperfectly  conchoidal,  uneven.  Hardness  6.5. 
Sp.  gr.  3.39.  Primary  form  a  right  rectangular  prism. 
Cleavage  parallel  'to  all  its  planes.  The  general  form  of 
the  crystals  quadrangular  ;  one  or  more  of  the  solid  lateral 
edges  often  replaced.  Faces  often  furrowed  or  streaked 
longitudinally. 

Compound  varieties. — Composition  granular,  and  some- 
times columnar, 

1.  Before  the  blow-pipe  on   charcoal,   pyramidal  Garnet 
melts  easily  into  a  globule  of  a  dark  colour.     Some  varieties* 
as  Egerane,  furnish  a  green  globule. 

It  consists  of        Silex,  35.50 

Alumina,  33.00 

Lime,  22.25 

Oxide  of  iron,       7.50 

do  manganese,  0.25 

2.  Idocrase  was  first  discovered  among  the  ejected  miner- 
als of  Vesuvius,  hence  it  received  the  name  of  Vesuvian.     A 
variety  has  been  found  near  Egra  in  Bohemia,  which  was  then 
named  Egerane ;  the  only  difference  which  exists  between 

U 


158  GEM. 

them  is,  that  Egerane  occurs  in  longer  crystals,which  are  deep- 
ly streaked  and  less  perfectly  formed ;  the  other  appears  in 
short  prisms  and  is  bounded  by  a  greater  number  of  brilliant 
faces.  All  the  colours  form  a  continuous  series  to  which  no 
constant  limits  can  be  fixed.  A  variety  resembling  Egerane 
has  been  called  Loboite  and  Frugardite  ;  another  from  Telle- 
marken  in  Norway,  of  a  blue  colour,  and  containing  copper, 
has  been  termed  Cyprine. 

3.  Pyramidal  Garnet  has  been  found  at  Newton,  Sussex 
county,  N.  J.  associated  with  rhombohedral  and  dodecahedral 
corundum  ;  colour  yellowish- green.  Also  at  Salisbury,  Ct. 
crystalized  in  rhomboidal  dodecahedrons ;  colour  reddish- 
brown  with  brilliant  planes.  The  same  variety  has  been  found 
at  Chester,  Mass. 

2.  TETRAHEDRAL  GARNET. 

Telrahedral  Garnet,  or  Helvine.  Jam. 
Hclvine.    Phil.     C. 

Colour  wax-yellow,  inclining  to  honey-yellow  and  yel- 
lowish-brown, or  also  to  siskin-green.  Streak  white. 
Translucent  on  the  edges.  Lustre  vitreous,  inclining  to 
resinous.  Fracture  uneven.  Hardness  6.0 — 6.5.  Sp. 
gr.  3.10.  It,  occurs  in  crystals  whose  general  form  is  that 
of  a  tetrahedron,  but  it  yields  to  mechanical  division  par- 
allel to  all  the  planes  of  the  regular  octahedron. 

1.  Before  the  blow-pipe  it  melts  on  charcoal  in  the  reducing 
flame,  into  a  globule  of  the  same  colour  as  the  mineral  ;  it  be- 
comes dark  in  the  oxidating  flame,  and  the  fusion  is  more  diffi- 
cult.   It  consists  of 

Silex,  39.50 

Alumina,  15.65 

Oxide  of  iron,  37.75 

do.  magnesia,  3.75 

Lime,  0.50 

2.  It  has  been  found  only  at  Schwarzenberg  in  Saxony,  in 
beds  in  gneiss. 

3.  DODECAHEDRAL  GARNET. 

Garnet.    Phil.    C. 

Colour  red,  brown,  yellow,  green,  black  and  white,  the 
only  bright  ones  are  the  red  colours.  Streak  white* 


GEM. 


159 


Translucent... opake*  Lustre  vitreous,  inclining  to  res- 
inous, in  some  specimens  more  of  the  latter  than  the  former. 
Hardness  6.5—7.5.  Sp.  gr.  3.61  Grossular.  3.70 
Melanite.  3.76  Common  brown  garnet.  3.78  Pyrope. 
4.09  precious  Garnet.  4.20  precious  Garnet  of  Haddam. 
Cleavage  imperfect  and  difficult.  Primary  form  dodeca- 
hedron with  rhombic  faces. 

1.  2.  3. 


P  or  P' on  P  '  120°. 


Fig.  1.    Primary  form. 
gin6  of  Haiiy. 


P  on  c  160°  54* 
Pona  149  50 
a  on  e  169  6 


Fig.  2.    Trapezoedron.    Fig.  3.  Trtemar- 


1.  Before  the  blow-pipe  garnet  melts  pretty  uniformly  with- 
out effervescence  into  a  black  globule,  dull  externally  but  pre- 
senting a  vitreous  fracture. 

2.  The  numerous  colours  and  forms  'which  dodecahedral 
garnet  presents,  has  led  to  the  designation  of  several  varieties ; 
the  most  important  of  which  are  as  follows.     1.  Grossular , 
it  occurs  only  in  imbedded  crystals  of  the  forms  of  icosi tetra- 
hedrons, and  combines  with  the  dodecahedron.     Its  colours 
are  confined  to  asparagus-green  and  mountain-green,    2.  Py- 
reneite  occurs  in  imbedded  crystals  in  limestone,  colour  gray- 
ish-black and  grayish- white,  semi-transparent.    3.  Melanite, 
colour  velvet-black,  opake.  4.  Pyrope  occurs  in  grains,  trans- 
lucent, of  a  remarkable  blood-red  colour.    5.  Precious  garnet 
is  always  red  and  usually  crystalized  in  the  primary  form.'    6. 
Common  garnet  is  brown  and  dull.    7.  Colophonite  presents  a 
combination  of  colours  which  gives  a  peculiar  irridescence 
very  pleasing  to  the  eye,  it  occurs  mostly  in  grains  which  co- 
here but  feebly. 


160  GEM. 

3.  The  different  varieties  of  dodecahedral  Garnet  consist 
as  follows : 

Grossu-    Melan-  Precious  Colopho-  Pyre- 

lar.           ite.  garnet.      nite.  neite.  ^yr°Pe- 

Silex,                  44.        35.50  35.75  37.  43.  40. 

Alumine,               8.50      6.  27.25  13.50  16.  28.50 

Lime,                 3350    32.50  0.  29.  20.  3,50 

Oxide  of  iron,      12.        24.25  36.          7.50  16.  16.50 

do  manganese,  a  trace.    0.40  0.25      4.75  0.  0.25 

Magnesia,            0.          0.  0.          6.50  0.  10. 

The  Pyrope  contains  besides  the  above  elements,  2.11  per 
cent  of  chromic  acid. 

The  atomic  constitution  may  be  expressed  generally  thus — 
1  atom  of  bisilicate  of  protoxide  of  iron-f-2  atoms  of  silicate  of 
protoxide  of  manganese-f-2  atoms  of  silicate  of  alumina.  Those 
garnets  which  are  called  aluminiferous,  are  double  silicates  of 
alumina  and  one  or  two  of  the  four  bases,  protoxides  of  iron, 
manganese,  magnesia  and  lime.  If  the  protoxide  of  iron  pre- 
dominates, the  globule  after  fusion  is  coated  with  a  pelicle  of 
reduced  iron,  but  the  pelicle  becomes  thinner  as  the  other  ele- 
ments increase,  and  the  globule  is  more  vitreous. 

4.  A  few  less  distinct  varieties  have  been  noticed  by  differ^ 
ent  mineralogists  thus  :  Topazolite,  which  possesses  a  topaz 
yellow  colour,  and  Succinite  an  amber-yellow,  and  JHlochroite 
which  is  a  mixed  variety,  has  a  yellowish,  greenish  or  brown- 
ish-gray colour.     Manganesian    Garnet  contains  a  large  pro- 
portion of  oxide  of  manganese,  and  gives  before  the  blow-pipe 
with  borax  and  nitre,  a  violet  coloured"  globule. 

5.  Dodecahedral  Garnet  is  extremely  abundant  in  the  primi- 
tive rocks,  especially  gneiss  and  mica  slate. 

Precious  Garnet  is  found  abundantly  at  Hanover,  in  gneiss* 
At  Franconia,  fine  crystals  of  the  variety  termed  by  Haliy,  tri- 
cmargine,  represented  by  fig.  3.  See  Shepard's  Min.  journey, 
in  the  Journal  of  Science,  No.  37,  p.  132.  Colophonite,  at 
Willsborough,  N.  Y.  Allochroite  near  Baltimore,  Md.  JVIe- 
lanite  at  Chester,  Mass,  and  at  Franklin,  N.  J.  Manganesian 
Garnet  near  Philadelphia,  Pa.  Pyrope,  Chester  co.  Pa. 

Remarkably  large  brown  garnets  occur  at  Franklin,  N.  J. 

The/two  following  species,  the  Aplome  and  Cinnamon  stoner 
have  not  as  yet  been  determined  to  be  distinct  species,  hence 
they  are  placed  in  connexion  with  dodecahedral  Garnet. 


GEM, 


161 


1.    APLOMB, 

Colour  brown,  sometimes  yellowish.  Streak  white. 
Translucent  on  the  edges... opake.  Lustre  vitreous,  in- 
clining to  resinous.  Brittle.  Hardness  7.0 — 7.5.  Sp. 
gr-  3.44.  The  primary  form  is  supposed  to  be  a  cube. 
Cleavage  imperfect.  Fracture  uneven. 


P  on  P      90° 
e  on  e      120 
P  on  e     135 


1.  It  appears  like  garnet  before  the  blow-pipe.    It  is  found 
to  consist  of 

Silex,  40. 

Alumine,  20. 

Lime,  15.5 

•  Ox.  manganese,         2. 
Ferriferous  silex,        2. 

2.  It  occurs  on  the  banks  of  the  Lina  in  Siberia,  and  in  Saxo- 
ny and  Bohemia.     Rare. 

li»    CINNAMON    STONE,   Or   ESSONITE. 

Colour  intermediate  between  hyacinth-red  and  orange- 
yellow.  Streak  white.  Lustre  vitreous,  inclining  to 
resinous.  Transparent... translucent.  Hardness  7.0 — 
7.5.  Sp.  gr.  3.63.  Usually  massive,  with  traces  of 
cleavage  parallel  to  a  prism  of  102°  40'.  Fracture  un- 
even. 

1.  Before  the  blow-pipe  it  melts  easily  into  a  brownish- 
black  globule. 

It  consists  of      Silex,  38.80 

Alumina,  21.20 

Lime,  31.25 
Oxide  of  iron,         6.50    Klaprotk. 
14* 


162  GEM. 

2.  The  cinnamon  stone  cannot  be  considered  distinct  from 
the  garnet,  unless  its  crystaline  form  belongs  to  the  prismatic 
system,  and  the  optical  researches  of  Brewster  and  Biot  ren- 
der it  probable  at  least,  that  it  is  identical  with  the  dodecahe- 
dral  Garnet. 

5.  PRISMATOIDAL  GARNET. 

Prismatic  Garnet.    Jam.     Staurotide.    C. 
Staurolite.     Grenalite.    Phil. 

Colour  dark  reddish-brown.  Streak  white.  Lustre 
resinous  externally,  and  inclining  to  vitreous  on  a  recent 
fracture.  Translucent  only  on  the  edges... opake.  Frac- 
ture uneven.  Hardness  7.0 — 7,5.  Sp.  gr.  3.72.  Pri- 
mary form  a  right  rhombic  prism  «of  129°  20'  and  50° 
40'.  The  crystals  are  usually  modified  by  a  replacement 
of  its  acute  lateral  edges. 

1.  Before  the  blow-pipe  it  is  infusible.     It  consists  of 

Silex,  33. 

Alumine,  44. 

Lime,  3.84 

Oxide  of  iron,  13.00 

Oxide  of  manganese,    1.00     Vauqudin. 

2.  It  belongs  exclusively  to  primitive  rocks,  and  is  usually 
found  in  single  or  double  crystals,  in  the  form  of  a  cross,  in 
mica  slate.     It  is  associated  with  garnet  and  cyanite.     It  is 
abundant  in  most  places  where  mica  slate  is  the  prevailing 
rock. 

GENUS  XII.    ZIRCON. 

H=7.5 

HJ>.,  G=4.5— 4.7 

1.  PYRAMIDAL  ZIRCON. 

Pyramidal  Zircon.    Jam. 
Zircon.    Phil.    C. 

Colour  red,  brown,  yellow,  gray,  green  and  white; 
usually  dull,  unless  when  red.  Streak  white.  Transpa- 
rent,..epake.  Lustre  more  or  less  adamantine.  Hardness 


GEM. 


163 


7,5.  Sp.  gr.  4.50.  Primary  form  an  octahedron  with  a 
square  base,  affording  angles  on  the  natural  planes  of  84Q 
SO7  and  95°  40.'. 

2 


I 


P  on  u 
P  on  x 
1  on  u 
1  on  x 
Ion  s 


152°  8' 
150   5 
159  17 
142  55 
135   0 


Troost.    Jour.  Nat.  Sci.  vol.  ii,  p.  58, 

1.  Infusible  before  the  blow-pipe.    It  consists  of 

Zirconia,  69.00        70.00 

Silex,  26.50        25.00 

Oxide  of  iron,'  0.50          5.00    Klaproth. 

2.  There  are  three  varieties,  which  are  usually  distinguished 
by  particular  names.     The  Hyacinth,  Jargoon  and  Zirconite. 
The  Hyacinth  is  of  various  shades  of  red,  passing  into  orange- 
red.     Transparent. ..translucent.     Colours  bright.     Structure 
perfectly  lamellar,  and  yields  to  cleavage  parallel  to  the  faces 
of  the  primary  octahedron.     It  is  esteemed  as  a  gem.     The 
Jargoon  occurs  in  prismatic  crystals  of  a  grayish,  brownish  or 
reddish  colour.     Structure  irregular.    Opake.     Zirconite  is 
reddish-brown  and  nearly  opake. 

3.  Zircon  occurs  near  Philadelphia,  on  the  York  road,  ex- 
hibiting the  modifications  of  fig.  2,  termed  by  Haiiy  Zircon 
bisunitaine.     The  variety  Zirconite  is  found  in  Buncombe, 
N.  C.    Also  at  Warwick,  at  the  £ase  of  the  mountain  Eve, 
in  a  sienitic  granite. 


ff  If  17 -B 


164  GEM. 

GENUS  XIII.    GADOLIN1TE. 

H.=6.5— 7.0 
G.=4.0— 4.3 

I.  PRISMATIC  GADOLINITE. 

Prismatic  Gadolinite.    Jam. 
Gadolinite.    Phil.    C. 

Colour  greenish-black,  dark.  Streak  greenish-gray. 
Lustre  vitreous,  inclining  to  resinous.  Translucent  on 
the  edges... opake.  Hardness  6.5 — 7.0.  Sp.  gr.  4.23. 
Primary  form  an  oblique  rhombic  prism. 

Compound  varieties.  Massive.  Composition  impal- 
pable. Fracture  conchoidal. 

1.  Before  the  blow-pipe  it  decrepitates,  but  does  not  melt. 
If  heated  upon  charcoal,  it  incandesces  at  once,  and  becomes 
pale.     In  nitric  acid  it  forms  a  jelly.    It  consists  of 

Yttria,  45.00 

Protoxide  of  iron,  1 1 .43 

Protoxide  of  cerium,  17.92 

Silica,  25.80 

2.  Gadolinite  occurs  in  gneiss  and  granite,  along  with  feld- 
spar, albite  and  quartz.     It  is  found  at  Ytterby,  Finbo,  and 
Brodelbo  in  Sweden. 

The  following  minerals  are  placed  in  connection  with  the 
order  Gem,  but  the  precise  relation  of  some  of  them  is  not  ac- 
curately determined. 

1.  CHONDRODITE. 

Chondrodite.    Haiiy. 

Chondrodite.    Brucile.    Maclureite.    Phil. 

Colour  yellow,  reddish-yellow,  pale  straw-yellow,  brown, 
reddish-brown,  and  brick-red.  Colours  dull,  excepting  the 
bright-red.  Translucent... opake.  Lustre  vitreous,  inclin- 
ing to  resinous.  Brittle.  Hardness  6.5.  Sp.  gr.  3.19. 
Fraeture  foliated,  with  a.  cleavage  which  indicates  the 


GEM. 

doubly  oblique  prism*  as  the  primary  form*   M  on  T  75°r 
P  on  S  65°,  by  approximation*     Thompson. 

1.  It  fuses  with  difficulty,  but  soon  loses  its  colour,  and  be- 
comes opake. 

It  consists  of    Silex,  32.66 

Magnesia,  54.00 

Peroxide  of  iron,  2.33 
Fluoric  acid,  *  4.08 
Potash,  2.10 

Water,  1.00     Seybert. 

2.  The  atomic  constitution  is  expressed  by  1  atom  fluate  of 
magnesia+6  atoms  of  silicate  of  magnesia.     Thompson. 

3.  It  occurs  in  Sussex  county,  New-Jersey,  and  in  Orange 
county,  New-York,  in  various  places,  also  sparingly  in  the 
county  of  Worcester,  Mass.     Chondrodite  is  found  imbedded 
in  granular  limestone  of  a  highly  crystaline  structure. 

2.  FOSTERITE. 
FosUrite.     Ann.  of  Phil,  xxxvii.  p.  61. 

Colourless.  Surfaces  brilliant.  Translucent.  Scratches 
quartz.  It  occurs  in  prismatic  crystals  having  nearly  the 
same  dimensions  as  corundum.  Cleavage  distinct  per- 
pendicular to  the  axis. 

1.  It  consists  of  silica  and  magnesia.  It  is  found  near 
Vesuvius  associated  with  spinelle  and  green  pyroxene. 

3.  HYALOSIDERITE. 
Hyalosiderite.     Walchner.     Edin.  Jour,  of  Science,  vol  i.  p.  184. 

Colour  reddish  or  yellowish-brown.  Streak  a  cinna- 
mon colour.  Translucent  on  the  edges,  transmitting  a 
hyacinth-red  and  wine-yellow  colour.  Lustre  vitreous, 
on  a  recent  fracture,  but  metallic  on  an  exposed  surface, 
from  a  tarnish  which  it  acquires,  which  is  a  brass-yellow 
or  a  gold-yellow.  Fracture  small  conchoidal.  Hardness 
5.5.  Sp.  gr.  2,85.  Cleavage  at  right  angles  to  the  axis 
of  an  octahedron. 

*  The  general  form  of  some  of  the  most  distinct  crystals  which  bars  been 
observed,  is  that  of  a  very  low  octahsdton,  with  a  rectangular  base. 


166  GEM. 

1.  Before  the  blow-pipe  it  melts  into  a  black  globule,  which 
is  magnetic.    With  borax  it  becomes  black,  but  with  salt  of 
phosphorus,  greenish.    It  consists  of 

Silex,  31.63 

Protoxide  of  iron,      29.71 
Magnesia,  32.40 

Potash,  2.78 

Oxide  of  manganese,  0.48 
Chrome,  a  trace. 

2.  It  occurs  in  amygdaloid,  near  the  village  of  Sasbach  in 
Brisgaw.    It  resembles  the  chrysolite. 

4.  KNEBELITE. 

Colour  gray,  spotted  with  dirty-white,  brownish-red, 
brown  and  green.  Opake.  Lustre  glistening.  Hard. 
Brittle,  and  difficultly  frangible.  Fracture  imperfect 
conchoidal.  Sp.  gr.  3.71.  Massive.  Surface  uneven 
and  cellular. 

It  consists  of  Silex,  32.5 

Protoxide  of  iron,  32. 

Protoxide  of  manganese,       35. 

Dobereiner. 

6.  LIGURITE. 
Ligurit.    Leonhard.    Liguritt.    Phil. 

Colour  apple-green.  Streak  grayish-white.  Trans- 
parent...translucent.  Lustre  of  a  recent  fracture  interme- 
diate between  vitreous  and  resinous.  Fracture  uneven. 
Hardness  above  5.0.  Sp.  gr.  3.49.  It  is  said  to  occur 
in  oblique  rhombic  prisms  of  140°  and  40°. 

1.  It  consists  of  Silex,  57.45 

Alumine,  7.36 

Lime,  25.30 

Magnesia,  2.56 

Oxide  of  iron,  3.00 

Oxide  of  manganese,      0.50     Viviani. 

2.  It  has  been  found  only  on  the  banks  of  the  Stura,  in  the 
Appenines,  in  a  talcose  rock.    It  is  considered  a  gem,  and  is 
superior  in  hardness  to  the  chrysolite. 


GEM.  167 

'  [6.  MELLILITE. 
Mellite.    Jam.    Phil.    C. 

Colour  yellow,  inclining  lo  red  or  green.  Opake. 
Gives  sparks  with  steel.  Crystalizes  in  square  prisms. 
P  on  M  or  M'  90°.  M  on  M'  90°. 

1.  It  has  been  found  only  at  Capo  di  Bove  and  Tivoli,  near 
Rome,  in  lava. 

7.  SPH^RULITE. 

Colour  various  shades  of  brown  and  gray.  Translu- 
cent on  the  edges... opake.  Brittle.  Hard.  Scratches 
quartz.  Sp.  gr.  2.52.  Cleavage  none. 

1.  Before  the  blow-pipe  it  is  almost  infusible ;   the  edges 
only  becoming  coated  with  enamel.     It  occurs  in  small  round- 
ish masses,  sometimes  aggregated  in  the  botryoidal  form,  with 
a  fibrous  structure. 

2.  It  occurs  in  Pitchstone  and  Pearlstone,  in  Iceland,  Sax- 
ony and  Scotland.     It  is  nearly  related  to  Obsidian  in  respect 
to  composition. 

8.  SPINELLANE. 
Spinellane.     H.  NosSn.    Leonhard. 

Colour  grayish-black,  passing  into  ash-gray  and  brown. 
Lustre  vitreous,  inclining  to  resinous.  Sometimes  a 
whitish  play  of  light  parallel  to  the  faces  of  the  hexa- 
hedron. Hardness  5.5—6.0.  Sp.  gr.  2.28.  Primary 
form  a  rhombic  dodecahedron,  the  lateral  planes  of  which 
are  unduly  lengthened  so  as  to  give  the  general  form  of 
six-sided  prisms,  with  triedral  terminations.  P  or  P'  on 
P"  120°. 

1.  Before  the  blow-pipe  it  is  infusible,  whether  alone  or 
with  additions.  It  consists  of 

Silex,  43. 

Alumine,  29.50 

Lime,  1.50 

Soda,  19. 


1*68  ORE. 

Oxide  of  iron,  2. 

Sulphur,  1. 

Water,  2.50    Klaprotii. 

2.  It  is  found  on  the  shores  of  Lake  Laach.  It  resembles 
Pitchstone,  according  to  Dr.  Brewster,  when  examined  in  thin 
splinters  under  a  powerful  microscope. 

9.  ZEAGONITE. 

AbrazilK.    Zeagonite.     Gismondine.    Phil. 

Colour  pale  smalt-blue,  milk-white,  rose-red.  Trans- 
lucent in  small  crystals.  Lustre  adamantine.  Fracture 
conchoidal.  Hardness  7.0 — 7.5.  It  crystalizes  in  oc- 
tahedrons with  a  square  base,  which  are  sometimes 
modified  by  replacements  of  the  edges  of  the  base.  P  on 
F  122°  54'.  P'  on  P'  85°  2'.  Brooke. 

1.  It  phosphoresces  before  the  blow-pipe,  but  does  not  fuse. 
It  gelatinizes  in  acids,  without  effervescence. 

It  consists  of        Silex,  41.4 

Lime,  48.6 

Alum,  2.5 

JMagnesia,  1.5 

Oxide  of  iron,  2.5    Carpi. 

2.  It  is  found  in  the  cavities  of  volcanic  rocks,  at  Capo  di 
Bove,  near  Rome. 

Zeagonite  differs  but  little  from  pyramidal  Zircon,  and  has 
often  been  considered  a  variety  of  it. 

ORDER  VIII.     ORE. 
GENUS  I.    TITANIUM-ORE. 

H=5.0— 6.5 
G=3.4— 4.4 

1.  PRISMATIC  TITANIUM-ORE. 

Prismatic  Titanium-ore,  or  Sphene.    Jam. 
Sphtne.    Phil. 

Colour  brown,  yellow,  gray,  green;  generally  dull, 
excepting  the  pistachio-green  ones.  Streak  white.  Lus- 
tre resinous,  inclining  to  admantine.  Transparent, .  .trans- 


ORE.  169 

lucent  on  the  edges.  .Hardness  5.0 — 5.5.  Sp.  gr.  3.46, 
of  a  massive  yellow  variety  from  Norway.  Primary  form 
an  oblique  rhombic  prism.  M  on  M'  133°  30'.  P  on  M 
or  M  121°  50'. 

1.  Before  the  blow-pipe  the  yellow  varieties  do  riot  change 
their  colour.    All  the  rest  become  yellow.     They  intumesce  a 
little,  and  melt  on  the  edges  into,  a  dark-coloured  enamel. 
They  dissolve  in  hot  nitric  acid,  and  leave  a  silicious  residue. 

It  consists  of        Lime,  33. 

Oxide  of  titanium,  33. 
Silex,  35.     Klaproth. 

2.  It  occurs  in  primitive  rocks,  chiefly  associated  with  py- 
roxene ;   more  particularly  with  the  variety  Sahlite. 

3.  It  is  found  at  various  places  in  the  counties  of  Orange,  N. 
Y.,  and  Sussex,  N.  J-    Also  at  Munroe  in  the  Highlands.     It 
is  found  of  a  straw-yellow  in  Chester  and  Middlefield,  Mass,, 
in  hornblende  rocks. 

2.  PERITOMOUS  TITANIUM-ORE. 
Prismato-Pyramidal  Tilanium-Ore.    Jam. 
Titanite,    Nigrine.    Phil. 

Colour  reddish-brown,  passing  into  red,  sometimes  yel- 
lowish. Streak  very  pale  brown.  Translucent.. .opake. 
Lustre  metallic,  adamantine.  Hardness  6.0 — 6.5.  Sp. 
gr.  4.24.  It  is  mechanically  divisible,  parallel  to  the  lat- 
eral planes  of  a  right  prism  with  square  bases.  Natural 
crystals  generally  striated  longitudinally,  and  frequently 
geniculated.  P  on  M  or  M'  90°.  M  on  M'  90°, 

1.  Before  the  blow-pipe  it  is  infusible  by  itself,  but  with  bo- 
rax it  gives  a  yellow  glass  in  the  reducing  flame.     When  far- 
ther acted  upon  it  assumes  an  amethyst  colour. 

It  consists  of    Titanium        32,  one  p. 
Oxygen  8,  one  p. 

2.  It  occurs  in  primitive  rocks  generally,  in  quartz  in  long 
striated  prisms,  which  are  exceedingly  brittle.     It  is  never 
abundant  at  one   place,  but  in  most  places  where  primitive 
rocks,  especially  hornblende,  occur,  we  may  expect  to  find  ti- 
tanium. 

15 


170  ORE. 

3.  PYRAMIDAL  TITANIUM-ORE. 

Pyramidal  Titanium-Ore,  or  Octahedrite.   Jam. 
Anatase.     Octahedrile.s  Phil. 

Colour  various  shades  of  brown,  more  or  less  dark ; 
also  indigo-blue.  Streak  white.  Lustre  metallic  ada- 
mantine. Semi-transparent... translucent.  Hardness  5.5 — 
6.0.  Sp.  gr.  3.82.  Structure  lamellar.  Primary  form 
an  acute  octahedron  with  a  square  base.  It  yields  to 
mechanical  division  parallel  to  the  faces  of  the  octahedron 
and  the  common  baSe  of  the  two  pyramids. 

1.  Before  the  blow-pipe  it  appears  like  the  preceding,  but 
the  Comte  de  Bournon  observes  that  some  crystals  acquire  by 
heat  the  property  of  acting  on  the  magnetic  needle.     It  is  con- 
sidered as  a  pure  oxide  of  titanium. 

2.  It  is  found  in  Dauphiny,  Switzerland,  Cornwall,  Eng. 
Norway,  Spain  and  Brazil. 

GENUS  II.    ZINC-ORE. 

H.=4.0— 4.5 
G -=5.4— 5.5 

1.  PRISMATIC   ZINC-ORE. 
Red  Oxide  of  Zinc.    Phil.     C. 

Colour  red,  inclining  to  yellow.  Streak  orange-yel- 
low. Translucent  on  the  edges.  Lustre  adamantine. 
Brittle.  Hardness  4.0—4.5.  Sp,  gr.  5.43. 

Compound  varieties. — Massive.  Composition  granu- 
lar. 

1.  On  exposure  to  air  it  becomes  dull.    Alone  it  is  infusi- 
ble, but  with  borax  it  yields  a  yellow  transparent  glass.     It  is 
soluble  with  effervescence  in  nitric  acid.     It  consists  of 

Oxide  of  zinc,  92. 

Oxide  of  manganese  and  iron,    8. 

2.  It  is  found  massive  in  large  quantities  in  Sussex  county, 
N.  J-,  associated  with  Franklinite. 


ORE.  171 

GENUS  III.    COPPER-ORE. 

H.=2.5— 4.0 
G.=5.6— 6.0 

1.  OCTAHEDRAL  COPPER-ORE. 

Colour  between  cochineal-red  and  lead-gray ;  also 
pure  cochineal-red,  and  when  in  capillary  crystals  almost 
carmine-red  and  crimson-red.  Surfaces  occasionally  irri- 
descent,  sometimes  black.  Lustre  adamantine,  and  some- 
times metallic  adamantine,  or  imperfect  metallic.  Streak 
several  shades  of  brownish-red,  shining.  Semi-transpa- 
rent...translucent  on  the  edges.  .  Brittle.  Hardness  3.5 
— 4.0.  Sp.  gr.  5.99.  Structure  lamellar.  Primary 
form  a  regular  octahedron,  under  which  form  it  often  ap- 
pears. 

1  2345 


[Figures  6  and  7  omitted.] 

Fig.  1.  Primary  crystal.  Fig.  2.  Octahedron,  with  the  solid  angles 
replaced  by  quadrangular  planes.  Fig.  3.  The  planes  complete, 
forming  the  cube.  Fig.  4.  Octahedron,  with  the  edges  replaced  by- 
six-sided  planes.  Fig.  5.  Those  planes  complete,  forming  the  rhom"- 
bic  dodecahedron.  Fig.  6.  The  octahedron,  whose  edges  are  bev- 
elled. Ffg.  7.  Octahedron  whose  solid  angles  are  replaced  by  four 
triangular  planes. 

Compound  varieties. — Massive.     Composition  granu- 
lar.    Individuals  of  various  sizes,  sometimes  impalpable. 

1.  Before  the  blow-pipe  on  charcoal  in  the  reducing  flame, 
metallic  copper  is  obtained.     It  dissolves  with  effervescence 
in  nitric  acid. 

It  consists  of        Copper    64,  one  p. 
Oxygen       8,  one  p. 

2.  The  oxide  of  copper  sometimes  contains  oxide  of  iron. 
The  colour  is  then  brown  or  dark-brown,  with  resinous  lustre. 


172  ORE. 

It  is  denominated  Tile-ore,  of  which  there  are  two  varieties — 
earthy  and  indurated  Tile-ore.  Of  the  red  copper  ore  there 
are  three  sub-species,  the  foliated,  capillary  and  compact. 

Octahedral  copper-ore  occurs  in  beds  and  veins  in  several 
rocks.  It  is  highly  valued  as  an  ore  of  copper. 

GENUS  IV.     TIN-ORE. 

H.=6.0— 7.0 
G.=6.3— 7,1 

1.  PYRAMIDAL  TIN-ORE. 

Pyramidal  Tin- Ore.    Jam. 
Oxide  of  Tin.    Phil.     C. 

Colour  various  shades  of  white,  gray,  yellow,  red, 
brown  and  black.  Streak  pale  gray;  in  varieties  pale 
brown.  Semi-transparent.. ..opake.  Lustre  adamantine. 
Brittle.  Hardness  6.0 — 7.0.  Sp.  gr.  6.96  of  crystalled 
variety — 6.51  thin  columnar  composition.  Primary  form 
an  obtuse  octahedron.  P  on  P,  133°  30'.  P  on  P  or  P' 
on  P'  112°  10',  over  the  summits. 

Compound  varieties. — Massive.  Composition  thin  co- 
lumnar ;  rarely  reniform  or  botryoidal.  Granular,  al- 
most impalpable,  and  strongly  connected.  Fracture  un- 
even. Tin-stone  or  Wood-tin  is  found  among  the  com- 
pound varieties. 

1.  Before  the  blow-pipe  the  oxide  of  tin  in  the  oxidating 
flame  takes  fire  and  burns  like  tinder,  and  is  converted  into 
the  peroxide.    This  does  not  fuse,  but  in  the  inner  flame,  if 
•well  regulated,  may  be  reduced  to  the  metallic  state.     With 
soda  on  charcoal  it  is  readily  reduced  ;   but  those  specimens 
which  contain  columbium  are  not  so  easily  reduced  without  the 
addition  of  a  small  quantity  of  borax. 

It  consists  of          Tin  58,  one  p. 

Oxygen        16,  two  p. 

2.  Oxide  of  tin  belongs  to  the  oldest  primitive  rocks,  or  the 
oldest  granite.     It  occurs  in  Cornwall,  Eng.,  also  in  Spain, 
and  Saxony.    A  single  specimen  in  crystals  has  been  found  ia 
Goshen,  Mass. 


ORE.  173 

3.  Tin  is  one  of  the  most  valuable  metals.  It  resists  for 
a  great  length  of  time  the  action  of  the  atmosphere  and  moist- 
ure. It  forms  alloys  with  lead  and  iron,  producing  compounds 
which  combine  properties  more  extensively  useful  than  can  be 
obtained  in  their  separate  states.  The  oxide  of  tin  also  forms 
an  essential  part  of  the  celebrated  scarlet  dye.  The  tin  of 
commerce  is  principally  obtained  from  the  pyramidal  Tin-ore. 

GENUS  V.    SCHEELIUM-ORE. 

H.=5.0— 5.5 
G.=7. 1—7.4 

1.  PRISMATIC  SCHEELIUM-ORE. 

Prismatic  Wolfram.    Jam.  ^ 

Wolfram.     Tungst ate  of  Iron.    Phil.    C. 

Colour  dark  grayish-black,  or  brownish-black,  or  brown. 
Streak  dark  reddish-brown.  Lustrejnetallic  adamantine. 
Opake.  Not  very  brittle.  llardness  5.0 — 5.5.  Sp.  gr. 
7.15.  Structure  lamellar.  It  yields  to  mechanical  di- 
vision parallel  to.  the  planes  of  a  right  oblique  angled  prism, 
which  is  the  primary  form. 


M  on  T  117°  22'. 

P  on  M  or  P  on  T  90°. 


1.  Before  the  blow-pipe  on  charcoal  it  may  be  fused  into 
a  globule  whose  surface  presents  a  collection  of  tolerably  large 
lamellar,  iron-gray  crystals,  having  a  metallic  lustre.  With  bo- 
rax it  fuses  readily.  With  salt  of  phosphorus  it  also  fuses 
easily,  and  in  the  reducing  flame  the  glass  becomes  dark-red. 
Sometimes  it  decrepitates  strongly.  Prismatic  Scheelium-ore 
consists  of 

Tungstic  acid,  78.77 

Protox.  manganese,      6.22 

Protox.  iron,  18  32 

Silex,  1.25 

15* 


ORE. 

2L  It  is  most  frequently  met  with  in  primitive  rocks  along 
with  pyramidal  Tin-ore,  both  in  veins  and  beds. 

It  is  found  in  Huntington,  Ct.  where  it  occurs,  both  massive 
and  crystalized,  in  octahedrons. 

GENUS  VI.    TANTALUM-ORE. 

H.=6.0 
G.=6.0— 6.3 

1.  PRISMATIC  TANTALUM-ORE. 

,      Prismatic  Tantalum- Ore.    Jam.     Columbile.    Phil. 

Colour  grayish  and  brownish-black.  Streak  dark 
brownish-black.  Opake.  Lustre  imperfect  metallic. 
Brittle.  Hardness  6.0.  Sp.  gr.  6.0.  Primary  form  a 
right  rectangular  prism.  General  form  of  the  crystals 
quadrangular  prisms,  which  are  generally  striated  lon- 
gitudinally and  variously  modified. 

Compound  varieties. — Massive.  Composition  granu- 
lar. 

1.  Before  the  blow-pipe  alone  it  suffers  no  change.     With 
borax  it  dissolves  slowly  but  perfectly.     The  glass  presents 
the  tint  of  iron  only  at  a  certain  point  of  saturation,  but  it  takes 
by  flaming  a  grayish-white  colour,  and  when  still  further  satu- 
rated,  it  spontaneously  becomes  opake  on  cooling.     As  long 
as  it  remains  transparent  its  colour  is  pale  bottle-green. 

Prismatic  Tantalum-ore  consists  of 

Oxide  of  tantalum,         75. 
Oxide  of  tin,  1. 

Oxide  of  iron,  17. 

Oxide  of  manganese,       5.     VogeL 

2.  This  scarce  and  interesting  mineral  was  first  found  in 
Haddam,  Ct.     It  has  since  been  found  in  Chesterfield. 

GENUS  VII.     URANIUM-ORE. 

H.=5.5  -    ' 

G.=6.4— 6.6 

1.  UNCLEAVABLE  URANIUM-ORE. 

Indivisible  Uranium,  or  Pitch- Ore.     Jam. 
Uran-  Ochre,    Pitch-blende.    Phil. 

Colour  grayish-black,    inclining    sometimes  to  iron* 


ORE.  175 

black,  also  to  greenish  and  brownish-black.  Lustre  im- 
perfectly metallic  and  sometimes  dull,  but  usually  resin- 
ous. Streak  black  and  a  little  shining.  Opake.  Frac- 
ture uneven  or  small  conchoidal.  Cleavage  none. 

Compound  varieties. — Massive.  Reniform,  globular. 
Composition  columnar,  impalpable.  Sometimes  there  is 
a  combination  of  carved  laminse  with  smooth  and  shining 
surfaces. 

1.  Alone  before  the  blow-pipe  it  does  not  fuse  ;  with  borax  it 
fuses   into  a  dark  yellow  glass   which   becomes  dirty  green  in 
the  oxidating  flame.     If  reduced   to  powder   it  is  slowly  so- 
luble in  nitric  acid.     It  consists  of 

Protoxide  of  Uranium,      86.50 
Protoxide  of  iron,  2.50 

Silex,  5. 

Sulphuret  of  lead,  6.       Klaproth. 

2.  Uncleavable  Uranium-ore  is  found  in   Cornwall,  Engv 
accompanied  with  various  ores  of  silver  and  led.     It  is  used  in 
painting  upon  porcelain,  and  yields  a  fine  orange  colour  in  the 
enamelling  fire  and  a  black  one  in  that  in  which  the  porcelain 
itself  is  baked. 

GENUS  VIII.    CERIUM-ORE. 

H.=5.5 
G.=4.9— 5.0 

1.  UNCLEAVABLE  CERIUM-ORE. 

Colour  intermediate  between  clove-brown  and  cherry- 
red,  passing  into  gray.  Lustre  adamantine.  Streak 
white.  Translucent  on  the  edges.  Brittle.  Hardness 
5.5.  Sp.  gr.  4.91.  Regular  forms  and  cleavage  un- 
known. 

Compound  varieties. — Massive.  Composition  granu- 
lar, nearly  compact.  Fracture  uneven,  splintery. 

1.  Alone  it  is  infusible,  but  with  borax,  it  forms  an  orange- 
yellow  globule  which  becomes  paler  on  cooling. 


176  ORE. 

1.  It  consists  of    Oxide  of  cerium,          68.59 

Silex,  18. 

Oxide  of  iron,  2. 

Lime,  1.25 

Water  and  carb,  acid,     9.60 

2.  This  rare  mineral  occurs  in  a  bed  of  gneiss,  at  tbe  cop- 
per mine  of  Nya  Bastnaes,  Sweden.    Accompanying  this  ore 
is  another  named  Cerine,  by  Berzelius,  but  too  little  known  to 
allow  its  being  received  into  the  system.     Colour  brownish- 
black.     Streak  yellowish-gray,  inclining  to  brown.    Hardness 
5.5—6.0.    Sp.  gr.  4.17. 

Before  the  blow-pipe  it  froths  and  melts  easily  into  an  opake 
shining  black  globule,  which  acts  upon  the  magnetic  needle. 
Also  with  borax  it  melts  easily,  and  forms  a  reddish  or  yellow- 
ish-brown bead.  It  consists  of 

Silex,  30.17 

Alumine,  11.31 

Lime,  9.12 

Oxide  of  barium,  28.19 
do.      iron,      20.72 

It  agrees  very  nearly  in  several  of  its  properties  with  Alla- 
nite. 

GENUS  IX.    CHROME-ORE. 

H.=5.5 

G.=4.4— 4.5 

1.  OCTAHEDRAL  CHROME-ORE. 

Colour  iron-black  and  brownish-black.  Streak  brown, 
Opake.  Lustre  imperfect  metallic.  Brittle.  Hardness 
5.5.  Sp.  gr.  4.49.  Fracture  uneven,  imperfect  con- 
choidal. 

Compound  varieties. — Massive.  Composition  granular ; 
individuals  of  various  sizes  and  generally  firmly  connect- 
ed. 

1.  Alone  it  is  infusible,  but  acts  upon  the  magnetic  needle 
after  having  been  acted  upon  in  the  reducing  flame.  It  is  dif- 
ficultly soluble  in  borax,  furnishing  a  beautiful  grass-green  glo- 
bule, It  consists  of 


ORE,  177 

Oxide  of  chrome,        43. 

Protoxide  of  iron,        34.70 

Alumine,  20.30 

Silex,  2. 

The  varieties  of  the  present  species  most  frequently  occur 
in  a  compound  state.  But  crystals  in  the  form  of  octahedrons 
are  said  to  occur  at  Hoboken,  N.  J.  and  at  the  Bare  Hills, 
near  Baltimore,  Md.  It  is  found  in  Serpentine  and  Talcose 
slate. 

2.  The  'octahedral  chrome-ore  is  a  valuable  mineral,  from 
which  is  extracted  the  oxide  of  chrome,  which  furnishes  with 
lead  a  fine  durable  yellow  pigment.  With  other  metals,  as 
cobalt  and  mercury,  it  yields  green  and  red  pigments  which 
are  used  for  painting  on  porcelain  and  for  painting  in  oil. 

GENUS  X.    IRON-ORE. 

H.i=5.0— 6.5 
G.=3.8— 5,3 

1.  AXQTOMOUS  IRON-ORE. 

Titanitic  Iron. 

Colour  dark  iron-black.  Streak  black.  Lustre  im- 
perfect metallic.  Opake.  Fracture  conchoidal.  Brittle. 
Hardness  5.0 — 5.5.  Sp.  gr.  4.66.  Primary  form  an 
acute  rhombohedron,  whose  plane  angle  at  the  apex  is- 
18°.  Bournon. 

It  consists  of  the  oxide  of  iron  and  the  oxide  of  titanium. 
Its  only  locality  is  the  department  of  the  Iserein  France. 

2.  OCTAHEDRAL  IRON-ORE. 
Octahedral  Iron- Ore.    Jam. 
Oxidulated  Iron.     Phil. 

Colour  iron-black.  Lustre  metallic,  in  some  varieties 
imperfect  metallic.  Streak  black.  Opake.  Brittle. 
Hardness  5.5 — 6.5.  Sp.  gr.  5.09.  Cleavage  parallel 
to  the  planes  of  the  regular  octahedron.  Generally  obedi- 
ent to  the  magnet. 


.V 

178  ORE. 


3. 


Fig.  1.  The  primary  $  the  regular  octahedron.  Fig.  2<  The  same 
With  the  edges  replaced,  and  by  an  enlargement  of  these  planes  the 
rhombic  dodecahedron  is  formed,  as  in  Fig.  3. 

Compound  varieties. — ^Massive.  Composition  granu- 
lar, coherence  of  the  individuals  variable.  Sometimes  it 
is  in  the  form  of  loose  sand. 

1.  Before  the  blow-pipe  it  is  infusible,  but  when  exposed  to 
a  great  heat  it  assumes  a  brown  colour  and  loses  its  magnetic 
properties.     It  dissolves  in  heated  muriatic  acid,  but  not  in 
nitric.        It  consists  of 

Protoxide  of  iron,         31. 

Peroxide  of  iron,          69.     BerzeKus. 

2.  Octahedral  iron-ore  occurs  principally  in  talcose  slate ; 
occasionally  in  other  rocks,  as  mica  slate,  hornblende,  chlorite 
slate  ;  also  in  serpentine  it  is  considerably  abundant. 

It  is  found  in  Hawley  and  Middlefield,  Mass.  Somerset,  Vt. 
and  in  the  counties  of  Essex  and  Orange,  N.  Y.  Also  at 
Baltimore,  Md. 

3.  DODECAHEDRAL  IRON-ORE. 
Franklinile.    Phil.     C. 

Colour  iron-black.  Lustre  metallic.  Streak  dark-brown. 
Opake.  Brittle.  Magnetic,  but  does  not  possess  polari- 
ty. Hardness  6.0 — 6.5.  Sp.  gr.  5.09.  Cleavage  im- 
perfect, parallel  to  the  planes  of  the  octahedron.  Fracture 
conchoidal.  Surfaces  always  smooth. 

Compound  varieties. Massive.  Composition  fine 

granular  ;  individuals  strongly  connected. 

1.  It  consists  of    Peroxide  of  iron,  66. 

Oxide  of  zinc,  17. 

Oxide  of  manganese,    1 6. 


ORE.  179 

It  dissolves  without  effervescence  in  heated  muriatic  acid. 
2.   It  is  found  at  Franklin,  N.  J.  associated  with  the  red 
oxide  of  zinc.     The  crystalized  variety  is  rare. 

4.  RHOMBOHEDRAL  IRON-ORE. 

Rhomboidal  Iron-Ore.    Jam. 
Specular*  Iron.     Red  Iron- Ore.    Phil. 

Colour  dark  steel-gray,  iron-black.  Lustre  metallic. 
Streak  cherry-red,  reddish-brown.  Surface  often  tarnish- 
ed or  irridescent.  Opake ;  very  thin  laminae  faintly  trans- 
lucent, and  show  a  deep  blood-red  colour.  Brittle.  Frac- 
ture uneven,  conchoidal.  Sometimes  shows  a  feeble  ac- 
tion upon  the  magnetic  needle.  Hardness  5.5 — 6.5.  Sp. 
gr.  5.25.  It  is  crystalized  in  many  forms,  which  are  de- 
rived from  a  slightly  acute  rhomboid  of  86°  10'  and  93° 
50'. 

Compound  varieties. — Globular,  reniform,  botryoidal 
and  stalactitic  shapes.  Composition  more  or  less  colum- 
nar, sometimes  impalpable.  Massive.  Composition 
granular,  passing  into  impalpable.  When  the  cohesion 
among  the  particles  is  diminished,  the  varieties  become 
scaly  and  glimmering,  the  granular  ones  earthy  and  dull. 

It  occurs  in  primitive  and  transition  rocks,  both  in  beds  and 
veins,  and  is  associated  with  oxidulated  iron. 

The  mines  of  this  substance  in  the  Island  of  Elba  are  of 
great  extent,  and  have  been  worked  it  is  said  upwards  of  3000 
years. 

5.  PRISMATIC  IRON-ORE, 

Prismatic  Iron- Ore.     Jam. 
Hydrous  Oxide  of  Iron.    Phil. 

Colour  various  shades  of  brown. ;  of  which  hair-brown, 
^clove-brown  and  blackish-brown,  are  the  most  common, 
Streak  yellowish-brown,  Lustre  adamantine.  Crystals 

*  Specular,  from  its  brilliancy. 


180  ORE. 

often  semi-transparent,  and  showing  a  blood-red  tint. 
Other  varieties  opake.  Brittle.  Exhibits  no  action  on 
the  magnet.  Hardness  5.0 — 5.5.  Sp.  gr.  3.92.  Sur- 
faces of  the  crystals  are  deeply  streaked  in  a  longitudinal 
direction.  The  primary  form  is  a  right  rectangular  prism, 
the  only  cleavage  being  parallel  to  the  plane  M.  P  on  M 
or  T  90°.  T  on  M  90°. 

Compound  varieties. — Globular,  reniform,  stalactitic 
and  fruticose  shapes.  Surface  often  drusy,  smooth,  gran- 
ulated. Composition  columnar.  Individuals  delicate, 
and  often  impalpable*  Composition  often  repeated. 
Massive.  Composition  columnar  or  impalpable.  Parti- 
.cles  often  slightly  coherent,  earthy,  dull. 

1.  Before  the  blow-pipe  it  becomes  black  and  magnetic.     It 
jnelts  with  borax  into  a  green  or  yellow  glass,  and  is  soluble 
in  heated  nitro-muriatic  acid.     It  consists  of 

Peroxide  of  iron,  82. 

Water,  14. 

Oxide  of  manganese,  2. 

Silex,  1. 

2.  Prismatic  Iron-ore  occurs  in  veins  and  beds,  associated 
with  braehytypous  Parachrose-baryte,   prismatic  Hal-baryte, 
&c.,  but  jiiore  generally  connected  in  this  country  with  granu- 
lar quartz  and  granular  limestone.     Several  varieties  are  in- 
cluded in  this  species.     The  fibrous  brown  Iron-ore,  or  brown 
Hematite,  are  crystalized,  but  are  compound  varieties  under 
imitative  shapes.     Compact  brown  Iron-ore  is  a  massive  vari- 
ety in  which  the  composition  is  not  discernable.     The  ochery 
brown  Iron-ore  is  an  earthy  variety,  with  texture  loose  and 
friable.     The  mixed  and  impure  varieties  of  this  species  are 
the  clay  Iron-ores  ;  as  the  granular,  common,  pisiform  and  the 
reniform  clay  Iron-ore.     It  is  an  important  ore,  and  is  used  ex- 
tensively in  the  manufacture  of  wrought  and  cast-iron.    The 
pig-iron  obtained  from  the  purer  varieties  with  charcoal  in  par- 
ticular, may  be  easily  converted  into  steel. 

3.  It  is  found  at  Salisbury,  Ct.,  Richmond  and  Lenox, 
Mass,  and  Bennington,  Vt.,  and  at  numerous  other  places  in 
the  United  States, 


ORE.  181 

1,  DI.PRISMATIC  IRON-ORE. 

Lievrite.    Jam. 

Liemrite.     Ytnite.    Phil.    C. 

Colour  intermediate  between  iron-black  and  dark-gray- 
ish-black, passing  into  greenish-black.  Lustre  imper- 
fect metallic.  Streak  black,  sometimes  inclining  to  green 
or  brown.  Opake.  Brittle.  Hardness  5.5 — 6.0.  Sp. 
gr.  3.99.  Primary  form  a  right  rhombic  prism.  M  on 
M'  1 10°  30'.  P  on  M  or  M'  90°.  It  admits  of  cleavage 
parallel  to  the  long  diagonal  of  the  prism. 

Compound  varieties. — Massive.  Composition  colum- 
nar, thin  and  straight.  Sometimes  fine  granular, 

1.  Before  the  blow-pipe  it  melts  easily  without  effervescence 
into  an  opake  glass,  which   is  magnetic.     Glass  of  borax  is 
coloured  yellowish-green.     It  is  soluble  in  muriatic  acid.    It 
consists  of 

Oxide  of  iron,  55. 

Silex,    ,  28. 

Lime,  12. 

Oxide  of  manganese,    3.     Descotils. 

2.  Di-prismatic  Iron-ore  is  found  at  Cumberland,  R.   I., 
along  with  Ferro-silicate  of  Manganese. 

GENUS  XI.    MANGANESE-ORE. 

H=2.5— 6.0 
G.=4. 0—4.8 

1.  PYRAMIDAL  MANGANESE-ORE. 

Foliated  Black  Manganese- Ore.    Jam. 
Manganese.    Phil. 

Colour  black,  or  brownish-black.  Lustre  imperfect 
metallic.  Streak  dark  reddish  or  chesnut-brown.  Opake. 
Hardness  5.0 — 5.5.  Sp.  gr.  4.72.  Primary  form  an 
octahedron  with  a  square  base.  Cleavage  parallel  fc>  all 
its  planes. 

16 


182  ORE. 


P  on  P"  or  P'  on  P"'  117°  30'. 
P  on  P' or  P"  on  P"' 105    45. 

Brooke. 


Compound  varieties. — Massive.  Composition  granu- 
lar. Particles  firmly  connected. 

1.  It  consists  of 

Per  and  protoxides  of  manganese,  75.80 
Silex,  15.17 

Alumine,  2.80 

Oxide  of  iron,  4.14 

2.  On  charcoal,  in  a  strong  heat,  it  fuses  on  the  edges  and 
preserves  its  gray-black.     With  borax  it  fuses  readily. 

2.  UNCLE AVABLE  MANGANESE-ORE. 

Compact  and  Fibrous  Manganese- Ore,  or  Black  'Hematite.    Jam. 
Black  Iron- Ore,  (in  part.)  Compact  Gray  Oxide  of  Manganese.  Phil. 

Colour  bluish-black  and  grayish-black,  passing  into 
dark  steel-gray.  Streak  brownish-black,  shining.  Lus- 
tre imperfectly  metallic.  Opake.  Brittle.  Hardness  5.0 
— 6.0.  Sp.  gr.  4.14.  Regular  form  and  cleavage  un- 
known. Fracture  not  observable. 

Compound  varieties. — Reniform,  botryoidal  and  fruti- 
cose  shapes.  Composition  columnar,  impalpable.  Frac- 
ture flat  conchoidal,  even.  Massive.  Composition  fine 
granular.  Particles  strongly  connected. 

1.  Before  the  blow-pipe  it  colours  the  glass  of  borax  violet- 
blue.     It  is  supposed  to  be  a  mixture  of  oxide  of  manganese 
and  iron. 

2.  It  is  associated  with  the  ores  of  manganese,  and  even  the 
ores  of  iron.     It  is  found  in  Saxony,  many  places  in  the  Hartz, 
and  in  Cornwall,  Eng. 


ORE.  183 

3.  PRISMATOIDAL  MANGANESE-ORE. 

Gray  Oxide  of  Manganese.     Phil. 

Colour  dark  steel-gray,  iron-black.  Lustre  metallic. 
Streak  brownish-black.  Opake.  Brittle.  Hardness  2. 5 — 
3.0.  Sp.  gr.  4.62.  Fracture  uneven.  Its  primary  form 
is  a  rhombic  prism.  P  on  M  or  M'  90°.  M  on  M' 
100°.  It  yields  to  mechanical  division  with  perfect  and 
brilliant  faces  parallel  to  the  lateral  planes  and  both  di- 
agonals of  the  primary  form. 

Compound  varieties. — Reniform  and  imitative  shapes. 
Surfaces  generally  rough  and  drusy.  Massive.  Compo- 
sition granular.  Particles  of  various  sizes.  Fracture 
uneven,  and  sometimes  earthy. 

1.  Before  the  blow-pipe  it  is  infusible.     With  borax  it  forms 
a  violet-blue  glass.     It  is  insoluble  in  nitric  acid.     In  heated 
sulphuric  acid  it  disengages  oxygen  gas.     Also  alone  with  a 
strong  heat.     It  consists  of 

Black  oxide  of  manganese,  90.50 
Oxygen,  2.25 

Water,  7.00 

2.  Prismatoidal  Manganese-ore  frequently  accompanies  the 
prismatic  and  rhombohedral  Iron-ores ;  sometimes  the  earthy 
variety  forms  a  bed  by  itself! 

3.  It  occurs  in  Cornwall,  Eng.,  and  in  the  Hartz,  Benning- 
ton,  Vt.,  Richmond,  Mass.,  both  earthy  and  compact.     It  is  a 
useful  mineral,  and  is  employed  in  the  manufacture  of  glass 
and  painting  in  enamel.     Also  valuable  in  chemical  operations, 
as  bleaching,  for  which  it  is  indispensable  in  furnishing  chlo- 
rine at  a  moderate  expense. 

4.  The  earthy  incoherent  variety  is  called  Black  Wad.    It 
occurs  as  a  coating  on  the  other  ores  of  manganese  and  the 
ores  of  iron.     Colour  brown.     Structure  compact.     Lustre 
rarely  imperfect  metallic,   generally  earthy  and  dull.     Sp.  gr. 
3. 76,  and  hardness  about  0. 5.     Sectile,  soils  and  writes.     It 
absorbs  water  rapidly.     It  consists  of 

Oxide  of  manganese,       68. 
Oxide  of  iron,  6.50 

Water,  17.50 


184  ORE. 

Carbon,  1. 

Baryta  and  silica,  9. 

Black  Wad  and  Brown  Iron-froth  are  very  similar  in  their 
mode  of  formation,  and  occur  under  the  same  imitative  shapes. 
5.  It  is  found  at  Cornwall,  Eng.,  and  in  the  Hartz. 

The  following  species  belong  to  the  order  Ore,  but  are  not 
sufficiently  known  to  be  arranged  in  the  system. 

1.  ALLANITE. 

Colour  brownish  or  greenish-black.  Streak  greenish- 
gray.  Lustre  imperfect  metallic.  Opake,  or  only  faintly 
translucent  in  thin  splinters,  transmitting  a  brownish 
light.  Brittle.  Hardness  6.0.  Sp.  gr.  4.00. 

1.  Alanite  froths  before  the  blow-pipe  and  melts  imperfectly 
into  a  black  scoria.     It  gelatinizes  in  nitric  acid. 

It  consists  of  Oxide  of  cerium,  33.90 
Oxide  of  iron,  25.40 
Silex,  35.40 

Lime,  9.20 

Alumine,  4.10 

2.  It  was  discovered  at  Alleck,  in  East  Greenland,  by  Sir 
Charles  Giesecke. 

2.  BROOKITE. 
Brookitc.    Levy.     Ann.  of  Phil.  Feb.  1825. 

Colour  hair-brown,  passing  into  a  deep  orange-yellow, 
and  some  reddish  tints.  Lustre  metallic  adamantine. 
Streak  yellowish- white.  Translucent.. .opake.  The  co- 
lours are  brighter  by  transmitted  light.  Brittle.  Hard- 
ness 5.5 — 6. 

1.  It  contains  titanium,  but  has  not  been  analyzed. 

2.  It  is  found  in  Dauphiny,  and  at  Snowden  in  Walesr  asso- 
ciated with  pyramidal  Titanium-ore. 

3.  FERGUSONITE. 

Fergusonite.    Haidinger.    Trans.  Roy.  Soc.  Edin. 
Allanite,  (in  part.)    Pbil. 

Colour  dark  brownish-black,  in  thin  splinters,  pale. 
Streak  yerjr  pale  brown,  like  peritomous  Titanium-ore* 


ORE.  196 

Lustre  imperfect  metallic,  inclining  to  resinous.  Opake  ; 
in  thin  splinters  translucent.  Brittle.  Hardness  5.5 — 
6.0.  Sp.  gr.  5.83  Allan.  5.80  Turner.  Not  mag- 
netic. 

1.  It  loses  its  colour  before  the  blow-pipe  and  becomes  pale 
greenish-yellow,  but  alone  is  infusible.  It  is  entirely  dissolved 
with  salt  of  phosphorus,  but  some  particles  remain  a  long 
time  unaltered.  The  pale  greenish  globule  becomes  opake  by 
flaming,  when  very  much  saturated,  or  on  cooling.  Before 
the  whole  portion  is  dissolved  it  assumes  a  pale  rose  colour 
in  the  reducing  flame.  It  is  described  by  Phillips,  and  Mohs 
in  the  German  original  of  his  work,  under  the  name  of  Yttro- 
tantalite. 
2.  It  is  imbedded  in  Quartz,  near  Cape  Farewell,  Greenland, 

4.  ORTHITE. 

Orthit.     Bereelius.     Orthite.    Phil. 

Colour  ash-gray,  passing  into  brown  by  decomposition. 
Streak  brownish-gray.  Opake.  Lustre  vitreous.  Form 
long  and  straight  "acicular  masses.  Massive.  Composi- 
tion impalpable.  Fracture  conchoidal.  Scratches  glass, 
though  with  difficulty.  Sp.  gr.  JJ.28. 

1.  Before  the  blow-pipe  it  froms*  becomes  yellowish-brown 
and  melts  with  effervescence  into  a  black  vesicular  globule, 
and  with  borax  into  a  transparent  one.     It  gelatinizes  in  heat- 
ed acids.     It  consists  of 

Silex,  32. 

Lime,  7.84 

Alumine,  14.80 

Oxide  of  cerium,  19.44 

Protoxide  of  iron,  12.44 

Oxide  of  manganese,  3.40 

Yttria,  3.44 

Water,  5.36 

2.  It  occurs  at  Finbo,  near  Fahlun,  in  Sweden,  along  with 
albite,  quartz  and  feldspar,  in  veins  traversing  gneiss. 

6.  PHOSPHATE  OF  MANGANESE. 
Phosphat  of  Manganese.    Jam.    Phi).     C. 

Colour  blackish-brown.     Streak  yellowish-gray.    Ltw- 
16* 


186  ORE. 

tre  resinous,  inclining  to  adamantine.  Translucent  on 
the  edges...opake.  Brittle.  Hardness  5.0 — 5.5.  Sp. 
gr.  3.43. 

1.  Before  the  blow-pipe  it  melts  easily  into  a  black  scoria, 
and  is  readily  dissolved  in  nitric  acid  without  effervescence. 

It  consists  of  Oxide  of  iron,  31. 

Oxide  of  manganese,  42. 

Phosphoric  acid,  27. 

2.  It  has  been  found  near  Limoges,  in  France,  in  granite. 

6.  STILPNOSIDERITE. 
Stilpnosiderite.    Jam.    Phil.     C. 

Colour  brownish-black,  blackish-brown.  Streak  yel- 
lowish-brown. Lustre  resinous.  Feebly  translucent  on 
the  edges... Opake.  Brittle.  Hardness  4.5.  Sp.gr.  3.61. 

1.  Before  the  blow-pipe  it  becomes  black,  but  is  infusible. 
With  borax  it  yields  a  dark  olive-green  glass,  but  is  not  melted 
itself^  ,|/0,,j 

It  consists  of       Oxide  of  iron,    80.25 
Silex,  3.75 

Water,  15. 

2.  It  is  supposed  to  contain  phosphoric  acid.     It  occurs  in 
Saxony  and  Thuringia,  and  in  the  Hartz.     It  is  smelted  as  an 
ore  of  iron,  and  has  been  considered  as  a  variety  of  prismatic 
Iron-ore. 

7.  YTTRO-TANTALITE. 
Yltro-Tanialile.   Jam.     Yllro-Columbite.    Phil. 

1.    BLACK   YTTRO-TANTALITE. 

Colour  black.  Streak  gray.  Imperfect  metallic  lus- 
tre. Opake.  Brittle.  Scratches  glass.  Sp.  gr.  5.39. 
Fracture  lamellar  in  one  direction,  coarse  granular  in  an- 
other. Indistinct  traces  of  crystalization. 

ii.    YELLOW   YTTRO-TANTALITE. 

Colour  yellowish-brown,  accidentally  spotted  or  striped 
with  green.  Lustre  resinous  on  the  surface,  vitreous  in 


METAL.  187 

the  fracture.  Opake.  Streak  white.  Scratches  glass 
with  difficulty,  but  is  very  distinctly  scratched  by  it. 
Sp.  gr.  5.88. 

lii.    DARK    YTTRO-TANTALITE.  ? 

Colour  black,  inclining  to  brown.  Streak  white.  Lus-i 
tre  intermediate  between  vitreous  and  resinous.  Very 
thin  fragments  translucent.  Almost  colourless;  some- 
times a  little  yellowish.  Hardness  equals  the  yellow  va- 
riety. 

1.  These  varieties  consist  of 

Black.  Yellow.  Dark. 

Oxide  of  tantalum,           57.00  59.50  51.81 

Yttria,                             20.25  24.90  38.51 

Lime,                                6.25  3.29  3.26 

Oxide  of  uranium,              0.50  8.23  1.11 

Tungstic  acid  with  tin,      8.25  1.25  2.59 

Oxide  of  iron,                    3.50  2.72  0.55 

ORDER  IX.    METAL, 
GENUS  I.    ARSENIC. 

H.=3.5 
G.=5.7— 5.8 

1.  NATIVE  ARSENIC. 

Native  Arsenic.    Jam.    Phil.    C. 

Colour  tin-white,  a  little  inclining  to  lead-gray,  very 
soon  tarnishes  and  becomes  dark-gray  on  being  exposed 
to  air.  Lustre  metallic.  Streak  unchanged,  rather  shin- 
ing. Brittle.  Hardness  3.5.  Sp.  gr.  5.76,  but  accord- 
ing to  Bergmann  that  of  melted  arsenic  is  8.30.  Regular 
forms  and  cleavage  unknown. 

Compound  varieties. — Generally  in  reticulated,  reni- 
form  and  stalactitic  shapes.  Composition  fine  granular 
and  often  compact. 


188  METAL. 

1.  Before  the  blow-pipe  it  exhales  the  odor  of  garlic  and 
copious  white  fumes  are  formed,  and  at  last  it  disappears. 

It  consists  of        Arsenic,  96. 

Antimony,  3. 

Oxide  of  iron  and  water,  1. 

It  is  generally  found  in  veins,  accompanied  by  several  spe- 
cies of  the  orders  Metal,  Pyrites  and  Glance. 

2.  It  occurs  rather  abundantly  in  the  mines  of  Minaberg, 
Schneeberg  and  Mareenberg,  in  Saxony. 

GENUS  II.    TELLURIUM. 

H.=2.0— 2.5 
G.=6.1— 6.2 

1.  NATIVE  TELLURIUM. 

Hexahedral  Tellurium.    Jam. 
Native  Tellurium.    Phil. 

Colour  tin-white.  Lustre  metallic.  Streak  unchang- 
ed. Rather  brittle.  Hardness  2.0.  Sp.  gr.  6.11.  Kla- 
proth. 

Compound  varieti.es. — Massive.  Composition  granu- 
lar and  sometimes  foliated.  Individuals  small. 

1.  Before  the  blow-pipe  on  charcoal  it  melts  easily  and 
burns  wuh  a  reddish-green  flame,  and  is  volatilized. 

Native  Tellurium  consists  of 

Tellurium,        92.55 
Iron,  7.20 

Gold,  0.25 

2.  It  has  been  found  in  Transylvania,  but  is  at  present  rare. 

GENUS  III.    ANTIMONY. 

H.=3.0 3.5 

G.=6.5—10.0 

1.  RHOMBOHEDRAL  ANTIMONY. 

Bodecahedral  Antimony.    Jam. 
Native  Antimony.    Phil. 

Colour  tin-white.  Lustre  metallic.  Streak  unchang- 
ed. Rather  brittle.  Hardness  3.0 — 3.5.  Sp.  gr.  6.64. 


Compound  varieties. — Reniform.  Composition  flatten- 
ed grains,  collected  into  curved  lamellae. 

1.  Before  the  blow-pipe  it  melts  quickly  into  a  globule  and 
burns  when  heated  to  redness,  even  if  the  blast  is  discontinu- 
ed.    It  emits  copious  white  vapours  which  are  deposited  round 
the  globule,  and  when   collected  form   prismatic  crystals  of 
oxide  of  Antimony. 

2.  The  present  species  was  found  at  Sahlberg,  near  Sahla, 
in  Sweden. 

2.  PRISMATIC  ANTIMONY. 
Octahedral  Antimony.    Jam. 
Antimonial  Silver.    Phil. 

Colour  silver-white,  inclining  to  tin-white.  Lustre  me- 
tallic. Streak  unchanged.  Hardness  3.5.  Sp.  gr.  9.44 
Hauy.  9.82  Klaproth. 

Compound  varieties. — Massive.  Composition  granu- 
lar, individuals  of  various  sizes  and  easily  separated. 

1.  Before  the  blow-pipe  the  fine  varieties  yield  a  globule  of 
silver,  while  the  antimony  is  driven  off.    Antimoniai  silver  con- 
sists of  from 

16 — 24  Antimony. 
76—84  Silver. 

2.  It  is  found  in  the  Hartz,  but  is  a  rare  mineral,  and  is  high- 
ly valued  for  the  silver  it  contains. 

GENUS  IV.    BISMUTH. 

H.  =2.0— 2.5 
G.=9.6— 9.8 

1.  OCTAHEDRAL  BISMUTH. 

Octahedral  Bismuth.    Jam. 
Native  Bismuth.     Phil. 

Colour  silver- white,  inclining  to  reddish-yellow.  Sub- 
iect  to  tarnish.  Lustre  metallic.  Streak  unchanged. 
6ectile  and  almost  malleable.  ,  Hardness  2.0 — 2.5.  Sp. 
gr.  9.73—9.61  the  melted  metal. 


190 


METAL. 


Compound  varieties. — Imbedded,  plumose  and  arbores- 
cent shapes.  Massive.  Composition  in  the  mass  foliated. 

1.  Before  the  blow-pipe  it  melts^easily,  even  fusible  in  the 
flame  of  a  candle.     On  charcoal  it  deposites  a  yellow  coating. 
It  is  soluble  in  nitric  acid  from  which  it  is  precipitated  white 
by  water. 

Octahedral  Bismuth  occurs  in  veins  in  granite  and  clay- 
slate. 

2.  It  is  found  at  Huntington,  Ct.  and  a  single  specimen  in 
the  county  of  Essex,  N.  Y.     It  enters  into  the  composition  of 
several  alloys  used  in  the  arts. 

GENUS  V.    MERCURY. 

H.=00.0 3.0 

G.=10.5— 15.0 

1.  'DODECAHEDRAL  MERCURY. 

Dodecahedral  Mercury,  or  Native  Amalgam.    Jam. 
Native  Amalgam.    Phil. 

Colour  silver-white.  Lustre  metallic.  Streak  un- 
changed. Brittle.  It  emits  a  grating  noise  when  cut  with 
a  knife.  Hardness  3.0—3.5.  Sp.  gr.  13.75.  Cleavage 
indistinct,  parallel  to  the  planes  of  a  dodecahedron.  Frac- 
ture conchoidal,  uneven.  Surface  smooth  and  shining. 

1.  There  are  two  kinds  of  Native  amalgam,  distinguished  in 
reference  to  the  solid  or  fluid  state  in  which  it  is  found.     The 
fluid  varieties  are  solutions  of  the  solid  or  pure  Mercury. 

Dodecahedral  Mercury  consists  of 

Silver,        36.00  27.00 

Mercury,    64.00  72.50 

Klaproth.  Cordier. 

2.  It  is  always  found  in  repositories  of  peritomous  Ruby- 
blende.     Before  the  blow-pipe  the  mercury  is  driven  off,  and 
a  globule  of  pure  silver  is  obtained. 

2.  FLUID  MERCURY. 

Fluid  Native  Mercury.    Jam. 
Native.  Quicksilver.     Phil. 

Amorphous.  Liquid.  Lustre  metallic.  Colour  tin- 
white.  Hardness  0.0,  Sp.  gr.  13.58.  Hauy. 


METAL.  19* 

1.  Fluid  Mercury  is  the  pure  metal  as  produced  by  nature, 
It  is  entirely  volatile  before  the  blow-pipe,  and  easily  soluble  in 
nitric  acid. 

2.  It  occurs  at  Idria  in  Carniola,  and  Almaden  in  Spain. 
The  quantity  of  Fluid  Native  Mercury  is  small ;  the  metal  is 

employed  for  'making  thermometers  and  barometers,  also  in 
various  chemical  preparations,  in  the  amalgamation  of  gold 
and  silver  ores  ;  in  the  production  of  artificial  amalgam  for 
silvering  mirrors,  and  for  gilding,  &c. 

GENUS  VI.    SILVER. 

H.=02.5 3.0 

G.=10.0— 10.5 

';  1.  HEXAHEDRAL  SILVER. 

Hexahedral  SUver.    Jam. 
Native  Silver.    Phil. 

Colour  silver-white,  more  or  less  subject  'to  tarnish. 
Streak  shining.  Lustre  metallic.  Ductile  and  malleable, 
fiardness  2.5 — 3.0.  Sp.  gr.  10.47.  Primary  form  a 
cube.  Cleavage  none.  Fracture  hackly. 

Compound  varied.— Dentiform,  filiform  and  capilla- 
ry shapes.  Massive.  Plates  formed  in  fissures  and  su- 
perficial coatings. 

1.  Native  silver  has  been  divided  into  common  and  aurifer- 
ous native  silver.  .  The  specific  gravity  and  yellow  colour  are 
the  distinct  marks  between  them,  but  it  is  not  determined 
whether  the  latter  is  a  species  or  variety,  as  the  gold  may  be 
only  in  juxta  position.     The  auriferous  native  silver  was  found 
to  consist  of       .Silver,  36.  72. 

Gold,  54.  26. 

2.  Native  silver   occurs   principally  in   veins   traversing 
gneiss,  clay-slate,  and  other  primitive  and  transition  rocks. 
The  mining  districts  of  Saxony  and  Bohemia,  but  more  par- 
ticularly those  of  Peru  and  Mexico,  furnish  it  in  the  greatest 
abundance.     Native  silver  is  said  to  occur  in  Michigan,  near 
Point  aux  Barques,  on  Lake  Huron,  in' gneiss. 

3.  Silver,  as  it  is  employed  in  coinage  and  plate,  is  well 
known.     It  is  also  useful  in  the  construction  of  chemical  and 
philosophical  apparatus,  for  which  it  must  be  perfectly  pure^ 
It  is  arso  used  in  pharmacy. 


METAL. 
.GENUS  VII.    GOLD. 

H.=  2.5 — 3.0 

G.=12.0— 20.0 

a.  HEXAHEDRAL  GOLD. 

Hexahedral  Gold.    Jam. 
Native  Gold.    Phil. 

Colour  various  shades  of  gold-yellow.  Streak  shining, 
lustre  metallic.  Ductile  and  malleable.  liardness  2.5 — 
.3.0.  Sp.  gr.  14.85  a  rolled  mass,  19.25  melted.  Hatiy. 
Primary  form  a  cube.  Cleavage  none.  Fracture  hackly. 

Compound  varieties. ^-Filiform,  capillary  and  abores-^ 
-cent  shapes.     Also  plates,  superficial  coatings  and  rolled 
masses. 

1.  Hexahedral  Gold  has  been  distinguished  into  gold-yel- 
low, brass-yellow  and  grayish-yellow  native  gold.     The  first 
is  the  purest  gold,  the  second  contains  silver,  and  the  last  pla- 
tina.     A  variety  of  the  brass-yellow  native  gold  yielded  Lam- 
padius,  Gold,        9660 

Silver,        2. 
Iron,  1.10 

Hexahedral  gold  melts  pretty  easily,  and  is  soluble  only  in 
.chlorine  or  nitro-muriatic  acid. 

2.  The  greatest  quantity  of  gold  has  been  found  in  the  allu- 
vial soil  in  Brazil,  Mexico  and  Peru.     It  is  also  found  in 
JVorth-Carolina,  and  various   other  places  in  the  southern 
states,  and  recently  in  Somerset,  Yt.     These  deposits  of  gold 
are  connected  with  the  Talcose  slate-rock,  and  may  be  found 
usually  wherever  the  protoxide  of  iron  forms  an  extensive  de- 
posit in  that  formation. 

GENUS  VIII.    PLATINA. 

H.=  4.0 4.5 

G.=l  6.0— 20.0 

1.  NATIVE  PLATJNA. 

Native  Platina.    Jam.     Phil.     C. 

Colour  perfect  steel-gray.  Streak  unchanged,  shining. 
JLustre  metallic.  Ductile.  Hardness  4.0 — 4.5.  Sp.  gr, 


METAL.  193 

17.33,  rolled  masses,  Irregular  forms,  grains.  Surface 
uneven,  or  worn  and  polished  by  attrition.  Cleavage 
none.  Fracture  hackly. 

1 .  Native  Platina  is  soluble  only  in  nitro-muriatic  acid.     It 
generally  contains  a  little  iron.     It  is  also  accompanied  by 
iridium,  osmium,  rhodium,  palladium,  copper,  chrome  and  ti- 
tanium. 

2.  Native  Platina  is  found  principally  in  South  America, 
in  the  provinces  of  Choco  and   Barbacoas.     Also  at  Matto 
Grosso,  in  Brazil.     Also  in  St.  Domingo.     Recently  it  has 
been  found  in  Russia,  in  the  Ural  mountains. 

"3.  The  refractory  property  of  this  metal  and  its  resistance 
to  almost  every  chemical  re-agent,  render  it  extremely  valua- 
ble in  the  construction  of  philosophical  and  chemical  appara- 
tus. It  is  also  used  for  covering  other  metals  ;  for  painting  on 
porcelain,  and  like  gold  and  silver  for  various  other  purposes. 
In  Russia  it  is  used  in  coinage. 

GENUS  IX.    IRON. 

H.=45 

G.=7.4— 7.8 

1.  OCTAHEDRAL  IRON. 

Octahedral  Iron.    Jam. 
Mive  Iron.     Phil. 

Colour  pale  steel-gray.  Streak  unchanged,  shining. 
Lustre  metallic.  It  exhibits  strong  action  on  the  magnet. 
Ductile.  Hardness  4.5.  Sp.  gr.  7.76  of  a  meteoric  va- 
riety from  Elbogen.  Primary  form  an  octahedron. 
Cleavage  none.  Fracture  hackly. 

1.  Octahedral  Iron  consists  of 

Jigram.  Siberia.  Mexico. 

Iron,      96.50  98.50  96.75 

Nickel,    3.50  1.50  3.25     Klaproth. 

It  resembles  pure  iron  in  most  of  its  chemical  and  physical 
properties,  but  is  not  so  liable  to  rust. 

2.  Masses  of  native  meteoric  iron  are  scattered  over  the 
continent  of  North  America.     The  most  remarkable  was  that 
discovered  in  Louisiana,  and  which  may  be  seen  in  the  cabinet 

17 


194  METAL. 

of  the  Lyceum  of  Natural  History  in  New-Yoak.  Native 
Terrestrial  Iron  is  found  in  Guilford  county,  North  Carolina, 
both  massive  and  under  the  primary  form  of  the  species.  Also 
in  Pennsylvania. 

GENUS  X.    COPPER. 

H.=2.5— 30 

G.=8.4— 8.9 

1.  OCTAHEDRAL  COPPER. 

Octahedral  Copper.    Jam. 
Native  Copper.    Phil.     C. 

Colour  copper-red.  Streak  unchanged,  shining.  Lus- 
tre metallic.  Ductile  and  malleable.  Hardness  2.5 — 
3.0.  Sp.  gr.  8.58.  Primary  form  a  cube.  Cleavage  none. 
Fracture  hackly.  Surface  rough.  It  is  liable  to  tarnish. 

Compound  varieties.-^— Plates,  dendritic  and  arbores- 
cent forms,  generally  superficial. 

1.  Before  the  blow-pipe  it  melts  pretty  easily,  but  is  cover- 
ed on  cooling  with  an  oxidised  coat.     Dissolves  easily  in  ni- 
tric acid,  and  yields  a  blue  solution  with  ammonia. 

2.  It  is  found  in  beds  and  veins,  and  is  associated  with  the 
ores  of  copper  and  sometimes  with  those  of  iron.     It  is  not  un- 
common in  the  native  state.    It  is  considerably  abundant  near 
Lake  Superior  and  sometimes  in  extraordinary  large  masses. 
It  is  often  connected  with  serpentine  rock.     Single  specimens 
have' been  found  in  various  places  in  the  soil. 

3.  Copper  is  extensively  applied  in  the  arts  and  manufac- 
tures, as  in  roofing  houses,  coppering  ship  bottoms,  coining, 
and  in  the  fabrication  of  various  utensils. 

IRIDIUM. 
Indium.     Jam. 
Jilloy  of  Iridium  and  Osmium.    Phil. 

Colour  pale  steel-gray.  Lustre  metallic.  Opake. 
Brittle.  Harder  than  native  Platina.  Sp.  gr.  19.5. 
Structure  lamellar.  When  crystalized  there  is  a  cleav- 
age parallel  to  the  terminal  planes.  Occurs  in  flattened 
grains. 


PYRITES.  195 

1.  If  melted  with  nitre  it  becomes  black,  but  again  acquires 
its  lustre  and  colour.  It  is  not  soluble  in  nitro-muriatic  acid. 
It  is  an  alloy  of  iridium  and  osmium,  and  is  found  in  South 
America  with  native  Platina. 

NATIVE  LEAD. 

Colour  pure  lead-gray.  Streak  shining.  Lustre  me- 
tallic. Malleable.  Fracture  hackly.  Hardness  1.5. 
Sp.  gr.  11.35.  Disagreeable  odour  by  friction. 

1.  It  melts  easily  before  the  blow-pipe,  and  covers  the  char- 
coal with  a  yellow  oxide. 

2.  Metallic  lead,  when  it  occurs  in  nature,  is  mostly  found 
in  circumstances  which  indicate  its  having  been  in  a  state  of 
fusion, 

PALLADIUM, 

Palladium.    Jam. 
Nalive  Palladium*     Phil. 

Colour  steel-gray,  inclining  to  silver-white.  Lustre 
metallic.  Hardness  superior  to  wrought  iron.  Sp.  gr. 
11.8  Wollaston.  12.14  Lowry.  Occurs  in  grains  and 
octahedrons  with  a  square  base. 

1.  With  nitric  acid  it  yields  a  red  solution.     By  itself  it  is 
infusible,  but  melts  with  sulphur.     The  pure  metal  is  ductile 
and  malleable,  and  flexible  in  thin  slips  but  not  very  elastic. 

2.  It  occurs  with  native  Platina  in  Brazil. 

ORDER  X.     PYRITES. 
GENUS  I.    NICKEL-PYRITES. 

H.=5.0— 5.5 
G.=7.5— 7.7 

1.  PRISMATIC  NICKEL-PYRITES. 

Prismatic  Nickel- Pyrites.    Jam. 
Copper  Nickel.    Arsenical  Nickel.     Phil. 

Colour  copper-red.  Streak  pale  brownish-black.  Lus- 
tre metallic.  Brittle.  Hardness  5.0 — 5.5.  Sp.  gr. 


196  PYRITESr 

7.65.  It  is  said  to  occur  in  six-sided  prisms.  Fracture 
imperfect,  conchoidal. 

Compound  varieties. — Massive.  Composition  fine  gran- 
ular, and  strongly  connected.  Fracture  uneven. 

1.  Before  the  blow-pipe  it  melts  on  charcoal  and  emits  an 
arsenical  smell.     The  metallic  lead  is  white  and  brittle.     In 
nitric  acid  it  soon  becomes  covered  with  a  green  coating.     It 
is  soluble  in  nitro-muriatic  acid. 

It  consists  of  Arsenic,         54.72 

Nickel,          44.20 
Iron,  0  33 

Lead,  0.32 

Sulphur,          0.40 

The  Arseniate  of  Nickel  which  is,  found  investing  the  pris- 
matic Nickel  pyrites,  is  produced  by  the  decomposition  of  the 
present  species,  and  consists  of  37.35  oxide  of  nickel  and 
&  little  cobalt,  36.97  arsenic  acid  and  24.32  of  water. 

2.  The  present  species  is  found  in  veins  at  Schneeberg, 
Annaberg,  and  other  mining  districts  of  Saxony. 

GENUS  II.    ARSENICAL-PYRITES. 

H.==5.0— 6.0 
G.=5.7— 7.0 

1.  AXOTOMOUS  ARSENICAL-PYRITES. 

Prismatic  Arsenical- Pyrites.    Jam. 

Colour  between  silver-white  and  steel-gray.  Streak 
grayish-black.  Lustre  metallic.  Brittle.  Hardness 
5.0 — 5.5.  Sp.  gr.  7.22.  Fracture  uneven.  Surface 
streaked. 

Compound  varieties. Massive.  Composition  fine 

granular,  often  impalpable,  and  the  individuals  are  strong- 
ly connected. 

Axotomous  Arsenical-pyrites  has  been  found  only  in  beds 
along  with  carbonate  of  iron  and  primitive  Iron  ore  in  Serpen- 
tine, near  Hiittenberg  in  Carinthia,  also  at  Schladming,  in 
Stiria. 


PYRITES.  197 

2.  PRISMATIC  ARSENICAL-PYRITES. 

Di-prismatic  Arsenical-  Pyrites.    Jam. 
Arsenical  Iron.    MispickeL     Phil. 

Colour  silver-  white,  inclining  and  passing  into  steel- 
gray.  Streak  dark  grayish-black.  Lustre  metallic.  Brit- 
tle. Hardness  5.5—6.0.  Sp.  gr.  6.12.  Primary  form 
a  right  rhombic  prism,  parallel  to'  its  planes  ;  it  admits  of 
mechanical  division.  Dimensions  111°  12'  and  68°  4S7. 

1.  Before  the  blow-pipe  on  charcoal  it  gives  out  copious  ar- 
senical vapours,  without  destroying  the  form  of  the  crystal. 
If  the  heat  is  continued  it  melts  into  a  globule  which  is  nearly 
pure  sulphuret  of  iron.     It  is  soluble  in  nitric  acid,  with  the 
exception  of  a  whitish  residue. 

It  consists  of  Iron,  36.04 

Arsenic,        42.88 
Sulphur,       21.68 

Prismatic  Arsenical-pyrites  occurs  in  beds  and  veins.  It  is 
often  accompanied  by  the  ores  of  silver  and  lead. 

2.  This  mineral  is  plentiful  in  the  mining  districts  of  Saxo- 
ny.    It  occurs  abundantly  in  the  town  of  Warwick,  Orange 
county,  N.  Y.  and  in  Franconia,  Ct. 

The  accidental  admixture  of  silver  renders  some  varieties 
useful  as  an  ore  of  that  metal.  It  sometimes  a)so  contains  a 
proportion  of  gold. 

GENUS  III.    COBALT-PYRITES, 


G.=6.1—  6.6 

1.  OCTAHEDRAL  COBALT-PYRITES, 

Octahedral  Cobalt-  Pyrites.    Jam. 
Bright  White  Cobalt.     Phil. 

Colour  tin-white,  inclining  to  steel-gray.     Streak  gray*- 
ish-black.      Lustre  metallic.     Brittle.      Hardness  5.5. 
Sp.  gr.  6.46.     Fracture  uneven.     Primary  form  a  cube* 
17* 


Fig.  1.  The  primary;  a  cube.  Fig.  2.  Cube  of  which  the  solid 
angles  are  replaced  by  triangular  planes.  Fig.  3.  These  planes  are  so 
increased  as  to  reduce  the  primary  planes  to  small  cubes  or  squares. 
In  Fig.  4.  the  primary  planes  entirely  disappear,  producing  the  regu- 
lar octahedron.  Fig.  5.  Is  a  pentagonal  dodecahedron  formed  by  a 
replacement  of  the  edges  of  the  cube,  by  irregular  six-sided  planes, 
alternately  in  different  directions. 

Compound  varieties. — Imitative  shapes  of  various  kinds. 
Massive.  Composition  granular,  individuals  generally 
small  and  strongly  connected.  Fracture  uneven. 

1.  Before  the  blow-pipe  it  emits  copious  arsenical  furnes 
and  melts  into  a  white  metallic  globule.     To  borax  and  other 
fluxes  it  imparts  a  blue  colour.    It  affords  a  pink  solution  with 
nitric  acid,  leaving  a  white  residue,  which  is  itself  dissolved 
on  farther  digestion. 

It  consists  of  Cobalt,  20.31 

Arsenic,         94.21 
Iron,  3.42 

Copper,  0.15 

Sulphur,  O.S8 

2.  Octahedral  Cobalt-Pyrites  is  principally  within  veins,  in 
rocks  of  various  ages.     It  is  accompanied  by  the  ores  of  silver 
and  copper.     It  is  a  valuable  mineral  for  the  preparation  of  the 
blue  enamel  colours,  but  particularly  smalt. 

The  Gray  Cobalt-ore  and  the  Radiated  White  Cobalt-ore, 
are  considered  by  Haliy  as  varieties  of  the  present  species,  but 
the  examination  of  some  individuals  indicate  that  they  belong 
to  the  prismatic  system,  but  they  are  too  imperfectly  known  to 
be  placed  in  the  order  Pyrites.     Both  varieties  are  brittle. 
Hardness  5.5.     Sp.  gr.  7.28.    The  radiated  white  variety  con- 
sists of  Cobalt,  28.00 
Arsenic,  6575 
Iron  and  manganese,    6.25 
>    The  radiated  variety  occurs  at  Schneeberg,  in  Saxony. 


PYRITES.  199 

2.  HEXAHEDRAL  COBALT-PYRITES. 

Hexahedral  Cobalt- Pyrites.    Jam. 
Bright  White  Cobalt.    Phil. 

Colour  silver-white,  inclining  to  red.  Streak  grayish- 
white.  Lustre  metallic.  Brittle.  Hardness  5.5.  Sp. 
gr.  6.29.  Fracture  imperfect  conchoidal,  uneven.  Cleav- 
age parallel  to  the  planes  of  a  hexahedron. 

Compound  varieties. — Massive.  Composition  granu- 
lar :  individuals  generally  small,  but  easily  discernible. 

1.  Before  the  blow-pipe  it  gives  upon  charcoal  a  large  quan- 
tity of  arsenical  fumes,  and  rnelts  only  after  having  been  roast- 
ed.    It  imparts  a  blue  colour  to  borax  and  other  fluxes,  and  is 
acted  upon  by  nitric  acid  in  a  manner  similar  to  the  preceding 
species. 

2.  It  occurs  at  Tunaberg  in  Sudermanland,  in  Sweden,  and 
in  Cornwall,  Eng. 

It  is  highly  valued  as  an  ore  of  Cobalt  for  painting  on  por- 
celain, and  manufacturing  smalt. 

GENUS  IV.     IRON-PYRITES. 

H. =3. 5— 6.5 
G.=4.4— 5.5 

Hexahedral  Iron-Pyrites,  or  Common  Iron-Pyrites.    Jam. 
Iron-Pyrites,  (in  part.)     Phil. 

Colour  bronze-yellow  in  different  shades,  sometimes 
steel-gray.  Streak  brownish-black.  Lustre  metallic. 
Brittle.  Hardness  5.03.  Sp.  gr.  4.6 — 4.8.  Primary 
form  a  cube.  It  yields  to  cleavage  parallel  to  the  planes 
both  of  the  cube  and  octahedron,  but,  the  cubical  planes 
are  more  brilliant  than  those  of  the  octahedron.  Fracture 
uneven. 

1.  2.  3*  4.  5. 


[*For  Fig.  3,  see  No.  3,  under  Cobalt-Pyrites  in  the  preceding  page.] 


200  PYRITES. 

Fig.  1.  Cube.  Fig:.  2.  Cube  with  the  solid  angles  replaced  by  tri- 
angular planes.  In  Fig.  3.  these  planes  are  so  increased  that  the  pri- 
mary planes  have  nearly  disappeared.  Fig.  4.  Is  the  octahedron 
completed.  Fig.  5.  Is  a  pentagonal  dodecahedron,  produced  by  the 
replacement  of  the  edges  of  the  primary  by  irregular  six-sided  planes, 
alternately  in  different  directions. 

Compound  varieties. — Globular,  capillary,  stalactitical 
and  pseudomorphous  shapes.  Massive.  Composition 
fine  granular.  Strongly  coherent.  Fracture  uneven. 

1.  Before  the  blow-pipe  on  charcoal  in  the  oxidating  flame 
it  becomes  red,  the  sulphur  is  driven  offand  the  iron  remains. 
At  a  high  temperature  it  melts  into  a  globule  which  is  magnet- 
ic. Some  varieties  are  subject  to  decomposition  on  exposure 
to  the  atmosphere.  It  consists  of 

Iron,  47.30 

Sulphur,      52.15 

Hexahedral  Iron-pyrites  constitutes  beds  by  itself  in  primi- 
tive slate.  It  is  frequently  mixed  with  coal  seams  and  the 
beds  of  clay  which  occur  along  with  them.  It  sometimes  con- 
tains gold  mechanically  mixed  with  it,  it  is  then  termed  aurif- 
erous Pyrites. 

The  present  species  is  a  very  common  mineral,  occuring  in 
almost  every  rock  formation. 

It  is  often  roasted  for  extracting  sulphur  ;  after  having  been 
exposed  to  the  oxidating  influence  of  the  atmosphere  it  yields 
sulphate  of  iron  and  sulphuric  acid, 

2.  PRISMATIC  IRON-PYRITES. 

Prismatic  Iron-Pyrites.    Jam. 
Iron-Pyrites,  (in  part )     While  Iron-Pyrites.    Phil. 

Colour  pale  bronze-yellow,  sometimes  inclining  to. 
green  or  gray.  Streak  grayish  or  brownish-black.  Lus- 
tre metallic.  Brittle.  Hardness  6.0 — 6.5.  Sp.  gr. 
4.67 — 4.84.  Primary  form  a  right  rhombic  prism.  M 
on  M'  106°  2'.  P  on  M  or  M'  90°.  Cleavage  rather 
perfect,  parallel  to  the  planes  of  the  preceding  prism.  It 
occurs  in  very  flat  crystals,  having  at  first  sight  the  ap- 
pearance of  dodecahedrons  with  triangular  planes,  but 
which  however  are  macles  consisting  of  similar  portions 
of  five  crystals. 


PYRITES.  201 

Compound  varieties. — Globular,  reniform,  botryoidal 
and  other  imitative  shapes.  Massive.  Composition  fine 
granular.  Fracture  even,  flat  conchoidal. 

1.  Before  the  blow-pipe  it  appears  like  hexahedral  Iron-py- 
rites.    Some  of  its  varieties  are  particularly  subject  to  decom- 
position.    It  consists  of 

Iron,  45.07 

Sulphur,  53.35 

Manganese,         0.70 
Silex,  0.80    Berzelius. 

2.  The  varieties  included  in  the  present  species  are  the 
RadiatedrPyrites,  Spear-Pyrites,  Cockscomb-Pyrites,  Hepa- 
tic-Pyrites, and  some  varieties  of  the   Cellular-Pyrites.     The 
distinction  among  the  varieties  depends  on  composition  and 
shape,  and  several  accidental  circumstances.     The  crystals  of 
Radiated-Py  rites  are  generally  simple.     Spear-Pyrites  is  found 
in  compound  crystals,  consisting  of  two,three  or  more  individu- 
als, regularly  grouped.      Cockscomb-Pyrites   occur  both   in 
simple  and  compound  crystals  of  a  particular  form,  with  inden- 
tations along  their  edges,  and  a  colour  much  inclining  to  green 
or  gray.     Hepatic-Pyrites   occurs  sometimes  in  pseudomor- 
phoses  of  six-sided  prisms.     It  decomposes  easily. 

The  varieties  of  this  species  are  very  useful  in  manufactur- 
ing sulphur,  sulphate  of  iron  and  sulphuric  acid. 

3.  RHOMBOHEDRAL  IRON- PYRITES. 

Rhomboidal  Iron- Pyrites,  or  Magnetic- Pyrites.    Jam. 
Magnetic  Iron-Pyrites.    Phil.     C. 

Colour  intermediate  between  bronze-yellow  and  cop- 
per-red. Streak  dark  grayish-black.  Lustre  metallic. 
Slight  action  on  the  magnet.  Brittle.  Hardness  3.5 — 
4.5.  According  to  the  Count  de  Bournon,  it  occurs  in 
irregular  six-sided  prisms,  variously  modified.  Cleavage 
parallel  to  the  terminal  planes  of  the  prism.  M  on  M 
120°.  P  on  M  or  M'  90°. 

Compound  varieties.—^ Massive.  Composition  granu- 
lar ;  individuals  of  various  sizes,  or  even  impalpable* 
Fracture  uneven. 


202  PYRITES. 

1.  It  consists  of    Iron,        59.85        56.37 

Sulphur,  40.15        43.63     Stromeyer. 
It  occurs  in  beds  along  with  other  minerals  containing  iron. 

2.  It  is  found  in  the  Hartz,  Siberia,  and  other  European 
countries. 

GENUS  V.     COPPER-PYRITES. 

H.=3.0— 4.0 
G.=4. 1—5.1 

1.  OCTAHEDRAL  COPPER-PYRITES. 

Variegated  Copper.    Jam. 
Purple  Copper.    Phil. 

Colour  intermediate  between  copper-red  and  pinchbeck- 
brown.  Streak  pale  grayish-black,  a  little  shining. 
"Rather  sectile.  Hardness  3.0.  Sp.  gr.  5.0.  Primary 
form  a  regular  octahedron.  General  form  of  some  crystals 
a  cube,  of  which  the  solid  angles  are  replaced.  It  yields 
to  mechanical  division  parallel  to  all  the  planes  of  the  re- 
gular octahedron. 

Compound  varieties. — Massive.  Composition  granu- 
lar. Individuals  strongly  connected.  Fracture  conchoid- 
al  and  uneven. 

1.  Before  the  blow-pipe  it  is  fusible  into  a  globule  which  is 
strongly  magnetic. 

It  consists  of  Copper,  61.07 
Sulphur,  23.75 
Iron,  14. 

Silex,  0.50     R  Phillips. 

2.  It  occurs  in  beds  and  veins  ;    the  crystalized  only  in 
veins.     The  crystalized   variety  is  found  only  at  Cornwall, 
Eng.  in  the  vicinity  of  Redruth. 

3.  It  is  a  valuable  mineral  for  extracting  copper. 

2.  PYRAMIDAL  COPPER-PYRITES. 
Octahedral  Copper- Pyrites.    Jam. 
Copper- Pyrites.     Yellow  Copper-Ore.    Phil. 

Colour    brass-yellow,    often    irridescent    externally. 


PYRITES.  203 

Streak  greenish-black,  a  little  shining.  Lustre  metallic. 
Rather  sectile.  Hardness  3.5 — 4.0.  Sp.  gr.  4,16.  Pri- 
mary form  an  octahedron  with  a  square  base.  The  gene- 
ral form  of  the  crystals  is  that  of  a  tetrahedron  having 
the  solid  angles  always  replaced.  Structure  perfectly 
lamellar. 

Compound  varieties. — GlobularJ  reniform,  botryoidal, 
stalactitic  and  other  imitative  shapes.  Surface  generally 
rough.  Composition  impalpable.  Massive.  Composi- 
tion granular.  Individuals  of  various  sizes,  often  impal- 
pable and  strongly  coherent.  Fracture  uneven  or  flat 
conchoidal. 

1.  Upon  charcoal  it  becomes  black  before  the  blow-pipe ; 
red  on  cooling.     It  melts  into  a  globule  whiqh  becomes  mag- 
netic if  kept  in  the  blast  for  sometime.     With  borax  it  yields 
a  globule  of  copper.     It  is  partly  soluble  in  dilute  nitric  acid  ; 
the  solution  is  green,,  and  the  undissolved  part  consists  of  sul- 
phur.    Pyramidal  Copper-Pyrites  consists  of 

Copper,          34.40  33.12 

Iron,  30.47  30. 

Sulphur,        38.87  36.52 

Silex,  0.27  0.39    H,  Rose. 

2.  It  is  frequently  found  in  beds  and  veins.     In  beds  it  is 
accompanied  with  the  ores  of  iron  and  copper.     The  black 
friable  substance  called  Copper-black,  is  the  product  from  the 
decomposition  of  pyramidal  Copper-pyrites,  and  also  from 
that  of  several  other  species.     If  pure  it  is  the  peroxide  of 
Copper. 

3.  It  is  found  in  most  of  the  mining  districts  of  Europe.     In 
the  United  States  at  the  Perkiomen  lead  mines,  Pa.,  at  Sing- 
sing,  and  various  places  on  the  Hudson,  Cheshire,  Simsbury, 
Ct.,  Southampton,  Mass. 

It  is  a  valuable  ore  for  the  extraction  of  copper. 

3.  COBALT-KIES. 

Pyrites? 

Cobalt-Kies.    Jam. 
Sulphuret  of  Cobalt.    Phil. 

Colour  pale'  steel-gray,   often   tarnished   copper- red. 


204  PYRITES. 

Lustre  metallic.  Semi-hard.  Massive-  Composition 
granular,  impalpable.  Individuals  indistinctly  cleavable. 
Fracture  conchoidal,  uneven. 

Compound  varieties. — Botryoidal.  Brilliant  exter- 
nally. 

1.  It  emits  a  sulphureous  odour  before  the  blow-pipe,  and 
after  having  been  roasted  it  communicates  a  blue  colour  to 
glass  of  borax. 

It  consists  of  Cobalt,  43.20 
Copper,  14.40 
Iron,  3.53 

Sulphur,      38.50 

2.  It  is  found  at  Riddarhyttan  in  Sweden,  associated  with 
pyramidal  Copper-pyrites,  and  hemi-prismatic  Augite-spar. 

4.  INICKELIFEROUS  GRAY  ANTIMONY. 

Nickeliferous  Gray  Antimony.    Jam. 

Colour  steel-gray,  inclining  to  silver-white.  Lustre 
metallic.  Brittle.  Hardness  5.0 — 5.5.  Sp.  gr.  6.45. 
Primary  form  a  cube,  to  the  planes  of  which  it  yields  a 
perfect  cleavage.  Massive.  Composition  granular. 

1.  Before  the  blow-pipe  it  is  partly  volatilized,  and  the 
charcoal  is  covered  with  a  white  coating.     It  at  last  melts  into 
a  metallic  globule,  which  communicates  to  glass  of  borax  a 
blue  colour.     It  consists  of 

Nickel,                       36.60  25.25 

Antimony,                   43  80  47.75 

Arsenic,"                       0.00  11.75 

Sulphur,                      17.71  15.25 

Iron  and  manganese,     1 .89  0.00 

Stromeyer.  Klaproth. 

2.  It  is  met  with  in  several  mines  in  the  principality  of 
Nassau,  along  with  hexahedral  Lead-glance,  and  pyramidal 
Copper-pyrites. 


GLANCE.  205 

ORDER  XL    GLANCE.  ' 
GENUS  I.     COPPER-GLANCE. 

H.=2.5—4.0 
G.=4.4— 5.8 

1.  TETRAHEDRAL  COPPER-GLANCE. 

Tetrahedral  Copper' Pyrites.    Jam. 
Fahlerz.     Gray  Copper.    Phil.    C. 

Colour  steel-gray,  passing  into  iron-black.  Streak  un- 
changed, sometimes  inclining  to  brown.  Lustre  metallic. 
Rather  brittle.  Hardness  3.0—4.0.  Sp.  gr.  5.10. 
Fracture  conchoidal,  of  different  degrees  of  perfection. 
Cleavage  indistinct,  parallel  to  the  planes  of  the  octahe- 
dron. Some  mineralogists  consider  the  tetrahedron  to  be 
the  primary  form.  P  on  P  70°  31'. 

1.  There  are  several  varieties  comprised  within  the  species 
tetrahedral  Copper-glance,  which  differ  much  from  each  other 
both  in  their  external  .characters  and  chemical  constitution, 
But  hitherto  it  has  not  been  possible  to  fix  on  those  distinctive 
characters  which  are  required   to  limit  particular   species. 
Hereafter,  it  is  probable  that  some  of  the  included  varieties 
will  constitute  separate  species  in  the  Natural  Historical  Sys- 
tem. 

2.  At  present  there  are  three  principal  varieties,  viz :  the 
Arsenical  Gray  Copper,  Antimonial  Gray  Copper,  and  Pla- 
tiniferous  Gray  Copper.     These  varieties  differ  much  in  their 
reaction  before  the  blow-pipe.     Some  yield  arsenic  and  others 
antimony  when  roasted,  and  the  residue  melts  in  different 
ways.     After  roasting  they  yield  a  globule  of  copper.    There 
are  varieties,  however,  which  contain  zinc,  mercury,  lead,  sil- 
ver and  gold. 

3.  The  present  species  occurs  in  most  of  the  mining  dis- 
tricts of  Europe. 

2.  PRISMATOIDAL  COPPER-G  LANCE. 
Prismatic  Antimony-  Glance.    Jam . 

Colour  blackish  lead-gray.    Streak  unchanged.    Lus- 

18 


GLANCE. 

tre   metallic.      Brittle.     Hardness  3.0.     Sp.   gr.   5.73. 
Fracture  conchoidal,  imperfect.     Surface  rough. 

1.  Prismatoidal  Copper-glance  is  nearly  allied  to  the  follow- 
ing species.     It  contains  sulphur,  antimony,  lead  and  copper, 
and  it  yields  a  little  silver.     It  gives  about  the  same  results 
before  the  blow-pipe. 

2.  It  is  found  at  St.  Gertraud,  near  Wolfsberg,  in  Carinthia. 

3.  DI-PRISMATIC  COPPER  GLANCE. 

Axifrangible  Antimony- Glance,  or  Bournonite.    Jam. 
Bournonile.     Triple  Sulphuret,    Phil. 

Colour  steel-gray,  inclining  to  blackish  lead-gray  or  iron- 
black.  Streak  unchanged.  Lustre  metallic.  Brittle. 
Hardness  2.5 — 3.0.  Sp.  gr.  5.76.  Primary  form  a 
right  rectangular  prism  of  93°  30'  and  86°  30'.  It  yields 
readily  to  mechanical  division,  and  furnishes  brilliant' 
planes  on  a  recent  face  of  cleavage.  Structure  perfectly 
lamellar. 

1.  Before  the  blow-pipe  on  charcoal  it  melts,  smokes,  and 
afterwards  yields  a  black  globule.     In  a  strong  heat  the  char- 
coal becomes  covered  with  oxide  of  lead.     It  is  easily  soluble 
in  heated  nitric  acid. 

2.  Di-prisma,tic  Copper-glance  has  been  found  in  Cornwall, 
associated  with  hexahedral  Lead-glance,  and  prismatoidal  An- 
timony-glance. 

4.  PRISMATIC  COPPER-GLANCE. 

Rhomboidal  Copper-Glance,  or  Vilreous  Copper.    Jam. 
Vitreous  Copper.    Sulphuret  of  Copper.    Phil. 

Colour  blackish  lead- gray,  occasionally  irridescent. 
Streak  unchanged,  sometimes  shining.  Lustre  metallic. 
Very  sectile.  Hardness  2.5—3.0.  Sp.  gr.  5.69,  of  a 
compact  variety.  It  is  found  crystalized  in  six-sided 
prisms  variously  modified. 

1.  In  the  oxidating  flame  of  the  blow-pipe  it  melts  and 
emits  with  a  noise  glowing  drops.  In  the  reducing  flame  it 
becomes  covered  with  a  coat,  but  doee  not  melt.  If  the  sul- 


GLANCE.  207 

phur  is  driven  off  a  globule  of  copper  remains.    In  heated 
nitric  acid  the  copper  is  dissolved,  and  the  solution  assumes  a 
green  colour,  and  the  sulphur  remains.     By  decomposition  it 
is  converted  into  black  copper. 
It  consists  of         Copper,        76.50 
Sulphur,       22. 
Iron,  0.50 

2.  It  is  one  of  the  most  common  .of  the  ores  of  copper,  and 
is  rich  and  valuable. 

GENUS  II.    SILVER-GLANCE. 

H.=2.0— 2.5 
G.=6.9— 7.2 

1.  HEXAHEDRAL  SILVER-GLANCE. 

Hexahedral  Silver- Glance.    Jam. 
Sulphuret  of  Silver.    Phil.     C. 

Colour  blackish  lead-gray.  Streak  shining.  Lustre 
metallic.  Subject  to  tarnish.  Fracture  small  conchoidal, 
uneven.  Surface  generally  rough,  uneven  and  possessing 
but  little  lustre.  Malleable.  Hardness  2.0 — 2.5.  Sp. 
gr.  7.19.  Traces  of  cleavage  parallel  to  the  planes  of  a 
dodecahedron. 

Compound  varieties. — Reticulated,  arborescent,  denti- 
form, filiform  and  capillary  shapes.  Individuals  not  al- 
ways distinguishable.  Some  of  the  imitative  forms  lon- 
gitudinally streaked. 

1.  It  intumesces  and  fuses  easily  before  the  blow-pipe,  and 
gives  a  globule  of  silver.     It  is  soluble  in  dilute  nitric  acid. 

It  consists  of  Silver,         85. 

Sulphur,      15.     Klaprofh. 

2.  It  is  found  in  veins  accompanied  with  a  great  variety  of 
the  ores  of  silver,  lead,  antimony  and  zinc.     It  is  found  in 
Mexico  and  Peru. 

3.  It  is  a  valuable  ore  of  silver,  and  is  the  one  principally 
employed  for  the  extraction  of  that  metal. 


208  GLANCE. 

GENUS  III.    LEAD-GLANCK 

H.=2.5 
G.=7.4— 7.6 

1.  HEXAHEDRAL  LEAD-GLANCE. 

Hexahedral  Galena,  or  Lead- Glance.    Jam. 
Galena.    Sulphuret  of  Lead.    Phil.     C. 

Colour  pure  lead-gray ;  by  decomposition  black  or 
blackish-gray.  Streak  unchanged.  Lustre  metallic. 
Rather  sectile.  Hardness  2.5.  Sp.  gr.  7.56.  Primary 
form  a  cube,  which  is  easily  obtained  by  mechanical  di- 
vision. 


Fig.  1.  Primary.  Fig.  2.  Cube  passing  into  the  octahedron.  Fig. 
3.  The  octahedrou  complete.  Fig.  4.  Octahedron  with  its  edges  re- 
placed. V, 

Compound  varieties. — Reticulated,  tabular  and  other 
imitative  shapes.  Massive.  Composition  fine  granular, 
passing  into  impalpable ;  the  colour  is  then  pale  lead- 
gray  ;  the  fracture  even  or  flat  conchoidal,  and  the  streak 
shining. 

1.  Before  the  blow-pipe,  if  heated  cautiously,  it  melts  and 
yields  globules  of  metallic  lead,  after  the  sulphur  is  driven  off. 

'  It  is  partly  soluble  in  nitric  acid,  and  leaves  a  whitish  residue. 
It  consists  of  Lead     104,  one  p. 

Sulphur  16,  one  p. 

2.  Hexahedral  Lead-glance  is  commonly  divided  into  the 
following  varieties,  viz :   Granular,   Compact,    Specular  or 
Slickensides,  Antimoniated  and  Argentiferous  Galena.    The 
Blue  Lead  is  only  the  common  galena,  in  the  form  of  rhom- 
bohedral  Lead-baryte.    The  Super- Sulphuret  of  Lead  is  an 
earthy  variety  of  a  bluish-gray  colour,  and  so  highly  inflamma- 
ble that  it  takes  fire  and  burns  on  being  held  in  the  flame  of  a 
candle. 


GLANCE.  209 

3.  The  present  species  is  a  very  abundant  mineral,  and  fur- 
nishes all  the  lead  of  commerce.  Remarkable  beds  of  it  are 
found  in  Missouri.  It  also  occurs  in  Southampton,  Mass. 
and  several  other  places  in  the  neighborhood  of  Southampton. 

This  mineral  sometimes  contains  a  sufficient  quantity  of  sil- 
ver to  make  it  profitable  to  work  for  that  metal.  It  sometimes 
also  contains  gold. 

GENUS  IV.    TELLURIUM-GLANCE. 

H.=l.  0—1.5 

G.=7.0— 7.1 
i 

1.  [PRISMATIC  TELLURIUM-GLANCE. 

Prismatic  Black  Tellurium.    Jam. 
Black  Tellurium.    Phil. 

Colour  blackish  lead-gray.  Streak  unchanged.  Lustre 
metallic.  Thin  laminae  highly  flexible.  Very  sectile. 
Hardness  1.0 — -1.5.  Sp.  gr.  7.08.  Crystalizes  in  small 
and  nearly  tabular  crystals.  Primary  form  a  right  square 
prism. 

1.  Before    the  blow-pipe  it  melts  easily  upon    charcoal, 
emits  white  fumes,  which  are  deposited  upon  the  charcoal  and 
gives  a  malleable  metallic   globule.     With  borax  it  gives  a 
bead  of  gold  containing  a  little  silver.     It  is  easily  soluble  in 
nitric  acid.     It  consists  of 

Tellurium,  32.20 

Lead,  54.00 

Gold,  9.00 

Silver,  0.50 

Copper,  1.30 

Sulphur,  3.00    Klaproth. 

2.  Its  chief  locality  is  Nagyag,  in  Transylvania. 

GENUS  V.    MOLYBDENA-GLANCE. 

H.=l.  0—1.5 
G.=4.4— 4.6 

lf  RHOMBOHEDRAL  MOLYBDENA-GLANCE. 

Rhomboidal  Molybdena.    Jam. 
.     Suljihurtt  of  Molybdtna.    Phil.     C. 

Colour  pure  lead  gray.     Streak  unchanged.     Lustre 

18* 


210  GLANCE, 

metallic.  Thin  laminae  highly  flexible.  Very  sectile, 
Opake.  Hardness  1.0 — 1.5.  Sp.  gr.  4.59.  It  crystal- 
izes  in  low  six-sided  prisms,  which  yield  to  cleavage 
parallel  to  the  terminal  planes. 

1.  Before  the  blow-pipe  it  does  not  melt  nor  is  it  reduced, 
but  emits  sulphureous  fumes  which  are  deposited  on  the  char- 
coal.    It  deflagrates  with  nitre,  and  is  soluble  with  efferves- 
cence in  nitric  acid,  leaving  a  gray  residue. 

It  consists  of       Molybdena    48,  one  p. 
Sulphur        32,  two  p. 

It  is  found  imbedded  or  disseminated  in  primitive  rocks,  as 
granite  and  gneiss. 

2.  It  is  found  near  Baltimore,  Brunswick,  Me.  Shaftsbury, 
Vt.  Brimfield,  Mass. 

GENUS  VI.    BISMUTH-GLANCE. 

H.=2.0— 2.5 
G.=6. 1—6.4 

1.  PRISMATIC  BISMUTH-GLANCE. 

Prismatic  Bismuth- Glance.    Jam* 
Sulphur et  of  Bismuth.    Phil . 

Colour  lead-gray,  inclining  a  little  to  steel-gray.  Streak 
unchanged.  Lustre  metallic.  Opake.  Rather  sectile. 
Hardness  2.0—2.5.  Sp.  gr.  6.54.  Brittle.  It  crystal- 
izes  in  small  crystals  deeply  striated  longitudinally.  They 
yield  to  cleavage  parallel  to  the  plane  P,  the  inclination 
of  which  on  the  lateral  planes  is  about  90°,  also  indica- 
tions of  cleavage  parallel  to  the  planes  of  a  right  rhombic 
prism  of  about  130°  and  50°. 

1.  It  melts  in  the  flame  of  a  candle.     Before  the  blow-pipe 
it  is  volatilized  and  covers  the  charcoal  with  a  yellow  areola. 
It  is  easily  soluble  in  nitric  acid,  and  Jhe  solution  yields  a 
white  precipitate  on  being  diluted. 

It  consists  of  Bismuth,        60. 

Sulphur,         40. 

2.  It  is  a  rare  mineral,  and  is  found  only  in  a  few  of  the  min- 
ing districts  of  Europe. 


GLANCE. 

GENUS  VII.    ANTIMONY-GLANCE. 

H.=1.5— 2.5 
G.  =4.2— 5.8 

1.  PRISMATIC  ANTIMONY-GLANCE. 

Graphic  Gold- Glance,  or  Graphic  Tellurium.    Jam. 
Graphic  Tellurium.     Graphic  Gold.    Phil. 

Colour  pure  steel-gray,  sometimes  tin-white.  Streak 
unchanged.  Lustre  metallic.  Opake.  Very  sectile. 
Hardness  1.5 — 2.0.  Sp,  gr.  5.72.  Fracture  even.  Brit- 
tle. Crystals  minute,  cleaving  easily,  but  the  primary 
form  is  unknown. 

Compound  varieties. — Massive.  Composition  imper- 
fectly columnar  or  granular,  small  but  not  impalpable. 

1.  The  prismatic  Antimony-glance  melts  easily  into  a  gray 
globule,  which  fumes  and  covers  the  charcoal  with  a  white  ox- 
ide.   After  continuing  the  blast  for  sometime,  a  ductile  metal- 
lic globule  is  obtained.     It  is  soluble  in  nitric  acid. 

It  consists  of  Tellurium,        60. 

Gold,  30. 

Silver,  10. 

2.  It  is  found  at  Offenbanya,  in  Transylvania.     It  is  a  valu-* 
able  ore  on  account  of  its  contents  of  gold  and  silver. 

2.  PRISMATOIDAL  ANTIMONY-GLANCE. 
Prismatic  Antimony- Glance,  or  Gray  Antimony.    Jam. 
Gray  Antimony.     Sulphur  et  of  Antimony.     Phi  I. 

Colour  lead-gray,  often  iridescent,  inclining  to  steel- 
gray.  Streak  unchanged.  Lustre  metallic.  Sectile. 
Opake.  Thin  laminse  slightly  flexible.  Hardness  2.0. 
Sp.  gr.  4.62.  Primary  form  a  right  rhombic  prism  of 
about  88°  30'  and  91°  3CK. 

1.  It  is  very  fusible  before  the  blow-pipe  and  is  absorbed  by  the 
charcoal.  By  continuing  the  heat  it  may  be  volatilized  with- 
out leaving  any  considerable  residue. 

It  consists  of  Antimony,        75. 

Sulphur,  25, 


GLANCE. 

2.  It  occurs  in  the  Hartz,  Cornwall,  Eng.  and  in  Scotland, 
associated  with  species  of  the  orders  Glance,  Blende  and  Hal- 
oide.  It  is  used  for  extracting  the  crude  antimony,  or  the 
metal  itself,  which  is  employed  in  the  manufacture  of  several 
metallic  alloys,  and  in  medicine. 

3.  AXOTOMOUS  ANTIMONY-GLANCE. 

Prismatoidal  Antimony- Glance,  or  Gray  Antimony  (in  part.)    Jam. 

Colour  steel-gray.  Streak  unchanged.  Lustre  metal- 
lic. Opake.  Sectile.  Hardness  2.0 — 2.5.  Sp.  gr. 
5.56. 

Compound  varieties. — Massive.  Composition  colum- 
nar ;  individuals  generally  very  delicate,  straight  and  par- 
allel, or  divergent. 

1.  Nothing  is  as  yet  known  of  the  proportions  among  the 
elements  of  the  present  species.     It  contains  sulphur,  antimo- 
ny and  lead. 

2.  The  axotomous  antimony-glance  is  a  rare  mineral.     It 
occurs  however  in  Cornwall,  in  masses  of  considerable  dimen- 
sions. 

GENUS  VIII.    MELANE*-GLANCE. 

H.=2.0— 2.5 
G.=5.9— 6.4 

1.  PRISMATIC  MELANE-GLANCE. 

Rhomboidal  Silver-Glance,  or  Brittle  Silver-Glance.    Jam. 
Brittle  Sulphur et  of  Silver.    Phil. 

Colour  iron-black,  dark-lead  or  bluish-gray.  Streak 
unchanged.  Lustre  metallic.  Opake.  Sectile.  Hard- 
ness 2.0 — 2.5.  Sp.  gr.  6.26.  Fracture  conchoidal.  Oc- 
curs crystalized  in  low  six-sided  prisms,  of  which  the  ter- 
minal edges  are  sometimes  replaced. 

1.  Before  the  blow-pipe  on  charcoal  it  yields  a  dark  colour- 
ed metallic  globule,  which  may  be  reduced  by  the  addition  of 
nitre,  or  soda  and  silex.  It  is  soluble  in  nitric  acid. 

It  consists  of        Silver,  66.50 

Antimony,  10. 

*  From  melas,  black. 


GLANCE.  213 

Iron,  5. 

Sulphur,  12. 

Copper  and  Arsenic,    0.50    Klaproth. 
2.  It  is  found  chiefly  in  Saxony,  along  with  other  silver 
ores. 

The  two  following  minerals  require  to  be  noticed  here,  a& 
they  seem  to  be  nearly  allied  to  the  preceding  species. 

i.    FLEXIBLE    SULPHURET    OP   SILVER.       Phil. 

Colour  dark  externally,  nearly  black.  Streak  shining, 
but  less  so  than  hexahedral  Silver-glance.  Lustre  metal- 
lic. Thin  lamina  flexible,  yields  readily  to  the  knife. 
Cleavage  perfect  parallel  to  P.  Primary  form  a  right 
oblique  angled  prism,  of  which  the  lateral  planes  incline 
to  each  other  alternately  at  angles  of  125°  and  55°.  Crys- 
tals minute,  shining  and  flexible. 

It  consists  of  silver,  sulphur  and  a  little  iron.  The  locality 
of  the  mineral  is  supposed  to  be  Hungary. 

il.     &ULPHURET    OF    SILVER   AND   ANTIMONY.      Phil. 

Colour  approaching  silver-white.  Lustre  metallic. 
Yields  easily  to  the  knife.  Sp.  gr.  5.5.  Primary  form 
a1  right  rhombic  prism  of  100°  and  80°.  Cleavage  per- 
fect. 

Before  the  blow-pipe  it  gives  off  copious  white  furoes  and  a 
slight  sulphureous  odor,  leaving  behind  a  white  metallic  glen 
bule.  It  consists  chiefly  of  antimony,  sulphur  and  silver. 

2.  ARGENTIFEROUS  COPPER-GLANCE. 

Argentiferous  Copper- Glance.    Jam. 
Sulphuret  of  Silver  and  Copper.    Phil. 

Colour  blackish  lead-gray.  Streak  shining.  Lustre 
metallic.  Perfectly  sectile.  Soft.  Sp.  gr.  6.25.  Frac- 
ture flat  conchoidal,  even.  Massive.  Composition  in> 
palpable. 


214  ,'       GLANCE. 

It  consists  of         '  Silver,  52.27 

Copper,  30.47 
Iron,  0.33 

Sulphur,  15.78     Strvmeyer. 

3.  BISMUTHIC  SILVER. 

Glance.  ? 
Bismuthic  Silver.    Jam.     Phil. 

Colour  light  lead-gray,  liable  to  tarnish.  Lustre  me- 
tallic. Opake.  Sectile.  Soft.  Occurs  in  acicular  and 
capillary  crystals.  Fracture  uneven. 

1.  It  melts  readily  before  the  blow-pipe,  covers  the  charcoal 
with  an  areola  of  the  oxides  of  lead  and  bismuth,  and  finally 
yields  a  silver  button.     It  is  dissolved  in  dilute  nitric  acid,  and 
yields  by  analysis 

Lead,  33. 

Bismuth,  27. 

.Silver,    '  15. 

Iron,  4. 30 
Copper,  0.90 

Sulphur,  16.30     Klaproth. 

2.  It  has  been  found  at  Schapback,  in  Baden.     It  is  used  as 
an  ore  of  silver. 

4.  COBALTIC  GALENA,  or  COBALTIC  LEAD-GLANCE. 

Colour  lead-gray,  inclining  to  blue.  Lustre  metallic, 
splendent.  Opake.  Soft.  Sectile.  Soils  a  little.  Very 
small,  moss-like  grouped  crystals.  Massive.  Composi- 
tion granular.  Individuals  cleavable.  Sp.  gr.  8.44. 

To  borax  before  the  blow-pipe  it  communicates  a  smalt-blue 
colour.  It  consists  of 

Lead,  62.89 

Arsenic,  22.47 

Sulphur,  0.47 

Iron,  2.11 

Cobalt,  0.94 

Arsenical  pyrites,  1.44 


GLANCE.  215 

5.  CUPREOUS  BISMUTH. 

Glance  f 
Cupriferous  Sulphuret  of  Bismuth.    Phil.    Jam. 

Colour  pale  lead-gray,  passing  into  steel-gray  and  tin- 
white,  subject  to  tarnish.  Lustre  metallic.  Streak  black. 
Opake.  Soft.  Sectile.  Massive.  Composition  colum- 
nar?  impalpable.  Fracture  uneven. 

1.  It  is  partly  soluble  in  nitric  acid,  leaving  the  sulphur  un- 
dissolved.     It  consists  of 

Bismuth,         47.24 
Copper,  34.66 

Sulphur,          12.58 

2.  It  occurs  in  the  principality  of  Fiirstenberg,  in  cobalt 
veins. 

6.  EUCAIRITE. 

Seleniuret  of  Silver  and  Copper.    Phil. 

Colour  lead-gray.  Streak 'shining.  Lustre  metallic. 
Opake.  Massive.  Composition  granular.  Cleavable. 
Soft. 

1.  Before  the  blow-pipe  it  melts  easily  and  emits  the  odor 
of  selenium.     It  is  soluble  in  boiling  nitric  acid, 

It  consists  of        Silver,  38.93 

Copper,  23.05 

Selenium,  26.00 

Foreign  substances,     8.90 

2.  It  is  found  in  Smaland  in  Sweden,  in  a  talcose  or  serpen- 
tine-like rock. 

7.  MOLYBDENA-SILVER. 
Molybd ena- Silver.    Jamv   Molyb die- Silver.    Phil. 

Colour  pale  steel-gray.  Lustre  metallic.  Not  particu- 
larly sectile.  Soft.  Elastic.  Sp,  gr.  8.0.  Cleavage 
perfect  parallel  to  the  planes  of  a  rhombohedron. 

1.  Before  the  blow-pipe  it  melts  easily  into  a  globule,  that 
can  be  entirely  volatilized,  during  which  the  supporting  char- 
coal is  covered  with  a  yellow  oxide.  If  dissolved  in  a  state  of 
powder  in  nitric  acid,  a  precipitate  of  sulphur  is  formed. 


216  GLANCE, 

It  consists  of        Bismuth,        95.  • 
Sulphur,  5. 

2.  It  has  been  found  in  Hungary,  associated  with  species  of 
the  genus  Lime-haloide,  Iron-pyrites,  &c. 

8.  NATIVE  NICKEL. 

Native  Nickel.    Jam.    Phil. 

Colour  brass-yellow,  inclining  to  bronze-yellow  and 
steel-gray.  Lustre  metallic.  Occurs  in  delicate  capil- 
lary crystals. 

1.  It  consists  of        Nickel,     64.35 

Sulphur,    34.26 

Before  the  blow-pipe,  it  melts  into  a  brittle  metallic  glob- 
ule. It  colours  the  glass  of  borax  blue.  In  nitric  acid  it  is 
dissolved  without  leaving  a  residue,  and  forms  a  pale  green 
solution. 

2.  It  occurs  in  Saxony  and  Bohemia  along  with  several 
species  of  Iron-pyrites  and  Lime-haloide. 

9.  NEEDLE-ORE. 

Needle-Ore.    Jam. 

Plumbo-cupriferous  Sulphuret  of  Bismuth.    PhiL 

Colour  blackish  lead-gray.  Lustre  metallic.  Fracture 
uneven.  Hardness  2.0 — 2.5.  Sp.  gr.  6.12.  Cleavage 
unknown,  imperfect.  Prismatic. 

1.  Before  the  blow-pipe  its  sulphur  is  driven  off,  and  it 
melts  and  emits  numerous  sparkling  and  metallic  globules. 
A  button  of  lead  containing  copper  remains,  which  communi- 
cates a  greenish-blue  colour  to  borax.    It  is  soluble  in  nitric 
acid,  and  consists  of  Bismuth,        43.20 

Lead,  24.32 

Copper,  12.10 
Nickel,  1.58  • 

Tellurium,  1.32 
Sulphur,  11.55 
Gold,  0.79  John. 

2.  It  occurs  at  Catharineburg,  in  Siberia,  imbedded  in: 
Quartz,  and  associated  with  Gold  and  several  species  of  the 
orders  Malachite,  Glance  and  Pyrites. 


GLANCE.  217 

10.  SELENIURET  OF  COPPER. 

Seleniuret  of  Copper.    Phil. 

Colour  silver-white.  Streak  .shining.  Lustre  metal- 
lic. Soft.  Malleable.  Massive.  Also  superficial  upon 
fissures  in  rhombohedral  Lime-haloide. 

1.  It  acquires  negative  electricity  by  friction.     It  melts 
easily  upon  charcoal  into  a  gray  malleable  globule,  giving  out 
a  strong  smell  of  selenium,  and  consists  of  selenium  and  cop- 
per. 

2.  It  has  hitherto  been  found  exclusively  in  a  copper  mine 
at  Smaland,  in  Sweden. 

11.  TENNANTITE. 

Tennantite.    Jam.    Phil. 

Colour  blackish  lead-gray.  Streak  reddish-gray.  Lus- 
tre metallic.  Opake.  Brittle.  Scratches  prismatic  and 
tetrahedral  copper-glance.  Sp.  gr.  4.37.  Cle'avage  pa- 
rallel to  the  planes  of  a  dodecahedron,  but  imperfect. 
Sometimes  massive,  with  a  granular  composition,  which 
passes  into  impalpable.  Fracture  even. 

1.  Before  the  blow-pipe  tennantite  decrepitates  a  little,  and 
burns  with  a  blue  flame,  emitting  copious  arsenical  vapors, 
and  melting  at  last  into  a  black  scoria,  which  is  magnetic. 

It  consists  of        Copper,       .  45.32 

Arsenic,  11.84 

Iron,  9.26 

Sulphur,  28.74 

Silex,  5. 

2.  It  occurs  in  several  of  the  Cornish  copper  mines,  in  vejns 
traversing  granite  and  clay-slate. 

12.  TIN-PYRITES. 

Colour  steel-gray,  inclining  to  yellow.  Lustre  metal- 
lic. Streak  black.  Opake.  Brittle.  Hardness  4.0. 
Sp.  gr.  4.35.  Massive.  Fracture  uneven,  imperfect 
conchoidal.  Composition  granular.  Strongly  coherent. 

19 


218  BLENDE. 

1.  Before  the  blow-pipe  the  sulphur  is  driven  off,  and  the 
mineral  melts  into  a  blackish  scoria,  without  yielding  a  metal- 
lic button.     It  is  soluble  in  nitro-muriatic  acid,  during  which 
the  sulphur  is  precipitated. 

It  consists  of  Tin,  34. 

Copper,      36. 
Iron,  2. 

Sulphur,      25.    Klaproth. 

2.  It  is  found  at  St.  Agnes,  in  Cornwall,  with  pyramidal 
Copper-pyrites. 

13.  YELLOW  TELLURIUM. 

Yellow  Gold-Glance,  or  Yellow  Tellurium.    Jam. 
Yellow  Tellurium.    Phil. 

Colour  silver-white,  much  inclining  to  brass-yellow. 
Opake.  Lustre  metallic.  Imbedded  "cry staline  laminse. 
Fracture  uneven.  Only  traces  of  cleavage.  Rather  brit- 
tle. Soft.  Sp.  gr.  10.67. 

1.  Before  the  blow-pipe  it  melts  into  a  metallic  globule  and 
emits  a  pungent  odor.     It  is  soluble  in  nitric  acid. 

It  consists  of         Tellurium,     44.76 
Gold,  26.75 

Lead,  19.50 

Silver,  8.50 

Sulphur,         0.50 

2.  The  only  locality  is  Nagyag  in  Transylvania,  where  it 
occurs    with    prismatic    Tellurium-glance    and    hexahedral 
Glance-blende,  &c. 

ORDER  XII.    BLENDE. 
GENUS  I.    GLANCE-BLENDE. 

H.=3.5— 4.0 
G.=3.9~4.05 

1.  HEXAHEDRAL  GLANCE-BLENDE. 

Prismatic  Manganese-Blende.    Jam. 
Sulphuret  of  Manganese.    Phil. 

Colour  iron-black ;  on  a  recent  fracture  dark  steel-gray. 
Streak  dark-green.  Lustre  imperfect  metallic.  Opake. 


BLENDE.  219 

Rather  sectile.  Hardness  3.5 — 4.0.  Sp.  gr.  4.01, 
Fracture  uneven,  imperfect  conchoidal.  Surface  rough. 
Primary  form  a  cube.  Cleavage  perfect ;  traces  of  cleav- 
age parallel  to  the  planes  of  a  dodecahedron. 

1.  Before  the  blow-pipe  it  is  melted  only  on  the  thinnest 
edges.     It  emits  sulphuretted  hydrogen  if  pulverised  and 
thrown  into  nitric  acid,  and  is  dissolved.     It  consists  of 

Protoxide  of  manganese,  82. 
Sulphur,  11. 

Carbonic  acid,  5. 

2.  It  is  a  rare  mineral.     It  occurs  chiefly  in  veins,  with  pris- 
matic Telhirium-glance,  at  Nagyag,  in  Transylvania. 

GENUS  II.    GARNET-BLENDE. 

H.=3.5— 4.0 
G.  =4.0— 4.2 

1.  DODECAHEDRAL  GARNET-BLENDE. 

Dodecahedral  Zinc-Blende.    Jam. 
Blende.    Sulphuret  of  Zinc.    Phil. 

Colour  green,  yellow,  red,  brown,  black ;  none  of  them 
bright.  Streak  white,  or  corresponding  to  the  colour. 
Lustre  adamantine.  Transparent... translucent.  Brittle. 
Hardness  3.5 — 4.5.  Sp.  gr.  4.07.  of  a  cleavable  varie- 
ty ;  4.02  of  a  compound  variety.  Primary  form  a  dode- 
cahedron. Cleavage  perfect.  Fracture  conchoidal. 


Fig.  1.  Primary,  a  rhombic  dodecahedron.  Fig.  2.  The  same,  of 
which  eight  of  the  solid  angles  are  replaced  by  as  many  triangular 
planes,  forming  a  passage  into  the  regular  octahedron.  Fig.  3.  The 
octahedron  complete.  Fig.  4.  The  octahedron,  with  the  solid  angles 
replaced  by  quadrangular  planes.  Fig.  5.  Those  planes  complete, 
forming  the  cube.. 


220  BLENDE. 

Compound  varieties. — :Reniform,  and  other  imitative 
shapes.  Surface  rough.  Composition  columnar,  often 
almost .  impalpable.  Massive.  Composition  granular, 
columnar,  and  sometimes  impalpable.  Fracture  uneven, 
or  even. 

1.  When  strongly  heated  in  the  oxidating  flame  of  the  blow- 
pipe it  gives  off  vapours  of  zinc,  which  form  a  coating  on  the 
charcoal,  but  it  does  not  melt.     It  is  soluble  in  nitric  acid, 
during  which  process  sulphuretted  hydrogen  is  disengaged. 

It  consists  of         Zinc       34,  one  p. 
Sulphur  16,  one  p. 
It  contains,  however,  from  one  to  twelve  per  cent  of  iron. 

2.  Dodecahedral  Garnet-blende  is  met  with  in  veins  and 
beds,  accompanied  chiefly  with  hexahedral  Lead-glance,  Iron- 
pyrites,  species  of  the  orders  Haloide  and  Baryte. 

3.  It  is  found  at  Southampton  and  Leverett,  Mass.,  Per- 
kiomen  lead  mines,  Pa.,  Hamburgh,  N.  J.,  in  the  Shawan- 
gunk  Mountains,  the  Highlands,  N.  Y.,  and  in  Berlin,  Ct. 

GENUS  III.     PURPLE-BLENDE. 

H.=l  0—1.5 
G.=4.5— 4.6 

1.  PRISMATIC  PURPLE-BLENDE. 

frismaiic  Antimony-Blende,  or  Red  Antimony.    Jain. 
Red  Antimony.    Phil. 

Colour  cherry-red.  Streak  cherry-red  or  brownish- 
red.  Lustre  common  or  metallic  adamantine.  Feebly  trans- 
lucent. Sectile.  Thin  laminae  are  slightly  flexible. 
Hardness  1.0 — 1.5.  Sp.  gr.  4.5 — 4.6.  Primary  form 
is  supposed  to  be  a  right  square  prism. 

Compound  varieties. — Tufts  of  capillary  crystals.  Mas- 
sive. Composition  thin  columnar,  straight  and  divergent 
from  common  centers. 

1.  Before  the  blow-pipe  it  melts  easily  Upon  charcoal  by 
which  it  is  absorbed,  and  at  last  entirely  volatilised.  Immers- 
ed in  nitric  acid,  it  is  covered  with  a  white  coating. 


BLENDE.  221 


It  consists  of  Antimony,  67.50 


Oxygen,  10.80 

Sulphur, 


Sulphur,  19.70 

2.  It  is  always  accompanied  with  prismatoidal  Antimony- 
glance.  It  occurs  in  veins.  It  is  found  in  Saxony,  Hungary, 
and  Dauphiny  in  France. 

GENUS  IV.    RUBY-BLENDE. 

H.=2.0—  2.5 
G.=5.2—  8.2 

1.  RHOMBOHEDRAL  RUBY-BLENDE. 

Rhomboidal  Ruby-Blende,  or  Red  Silver.    Jam. 
Red  Silver.    Ruby  Silver.    Phil. 

Colour  iron-black,  sometimes  passing  into  cochineal- 
red.  Streak  several  shades  of  cochineal-red,  or  corres- 
ponding to  the  colour  ;  in  some  varieties  it  is  aurora-red. 
Lustre  adamantine  :  metallic  adamantine  in  the  dark 
coloured  varieties.  Semi-transparent...  opake.  Sectile. 
Hardness  2.0  —  2.3.  Sp,  gr.  5.84.  Brittle.  Primary 
form  an  obtuse  rhomboid  of  108°  30'  and  71°  30'.  Struc- 
ture perfectly  lamellar. 

Compound  varieties.  —  Dendritic  and  scaly  forms.  Mas- 
sive. Composition  granular,  of  various  sizes  of  individu- 
als, strongly  connected. 

1.  It  decrepitates  before  the  blow-pipe  upon  charcoal,  melts 
and  emits  fumes  of  sulphur  and  antimony,  after  which  it  yields 
a  globule  of  silver.     It  is  soluble  in  dilute  nitric  acid. 

It  consists  of  Silver,  58.94 

Antimony,      22.84 
Sulphur,         16.60 

2.  Rhombohedral  Ruby-blende  has  been  found  at  only  a 
few  localities,  but  in  some  of  these  it  is  said  to  occur  in  con- 
siderable quantities.     It  is  found  in  the  mining  districts  of 
Saxony,  also  in  Mexico  and  Peru. 

It  is  a  valuable  mineral  for  the  extraction  of  silver,    The 
dark-red  varieties  yield  a  greater  quantity  than  the  light. 

19* 


222  BLENDE. 

2.  HE  MI-PRISMATIC  RUBY-BLENDE 

Dark-Red  Silver. 

Colour  iron-black.  Streak  dark  cherry-red.  Lustre 
intermediate  between  metallic  and  metallic-adamantine. 
Opake,  except  in  thin  splinters,  when  it  transmits  a  deep 
blood-red  colour.  Very  sectile.  Hardness  2.0 — 2.5.  Sp. 
gr.  5.22.  Fracture  imperfect  conchoidal. 

It  agrees  nearly  in  its  results  before  the  blow-pipe  with  the 
preceding  species.  It  contains  only  about  30...40  per  cent  of 
silver,  besides  sulphur  and  antimony.  Very  rare. 

3.  PERITOMOUS  RUBY-BLENDE. 

Prismato-rhomboidal  Ruby-Blende,  or  Cinnabar.    Jam 
Cinnabar.     Sulphuret  of  Mercury.    Phil. 

'Colour  several  shades  of  cochineal  red,  the  darker  va- 
rieties inclining  to  lead-gray.  Lustre  adamantine,  inclin- 
ing to  metallic  in  dark  coloured  varieties.  Streak  scarlet- 
Ted.'  Semi-transparent... translucent  on  the  edges.  Sec- 
tile.  Hardness  2,0 — 2.5.  Sp.  gr.  8.09.  Primary  form 
ua  acute  rhomboid  of  71°  48'  and  108°  12'.  Structure 
lamellar. 

Compound  varieties. — Rarely  in  imitative  shapes.  Mas- 
sive. Composition  fine  granular,  passing  into  impalpable 
in  some  varieties.  Fracture  uneven  or  even. 

1 .  Before  the  blow-pipe  the  pure  varieties  are  entirely  vola- 
tilized.    It  is  soluble  in  nitric  acid. 

These  two  varieties,  which  are  usually  known  under  distinct 
names,  are  the  Hepatic  Cinnabar  and  the  Bituminous  Cinna- 
bar. It  consists  of 

Mercury,        84.50 

Sulphur,          14.75 

2.  It  occurs  at  Idria  in  Carniola,  in'beds  of  bituminous  slate. 
Also  at  Almaden  in  Spain. 

,It  is  used  for  the  extraction  of  mercury  ;  when  very  pure  it 
may  be  employed  as  a  pigment  in  its  natural  state. 


SULPHUR.  223 

ORDER  XIII.    SULPHUR. 
GENUS  I.    SULPHUR. 

H. =1.5— 2.5 
G.  =1.9— 3.6 

1.  PRISMATOIDAL  SULPHUR. 

Yellow  Orpiment,  or  Prismatoidal  Sulphur.    Jam. 
Orpiment.    Phil. 

Colour  several  shades  of  lemon-yellow.  Streak  lemon- 
yellow,  generally  a  little  paler  than  the  colour.  Lustre 
metallic.  Pearly  upon  the  perfect  faces  of  cleavage,  for 
the  rest,  resinous.  Sectile.  Transparent... translucent  on 
the  edges.  Thin  laminae  flexible.  Hardness  1.5 — 2.0. 
Sp.  gr.  3.48.  Primary  form  a  right  rhombic  prism  of 
100°  and  80°.  It  yields  to  mechanical  division  parallel 
only  to  the  longer  diagonal  of  the  prism. 

Compound  varieties. — Reniform,  botryoidal  and  other 
imitative  shapes.  Massive.  Composition  granular,  of 
various  sizes  of  individuals. 

1.  Before  the  blow-pipe  upon  charcoal  it  burns  with  a  blue 
flame,  and  emits  fumes  of  sulphur  and  arsenic.  It  is  soluble 
in  nitric,  muriatic  and  sulphuric  acids. 

It  occurs  in  nodules  or  in  imbedded  crystals  in  blue  clay. 

*2.  It  is  found  in  Hungary,  near  Vienna,  and  at  Kapvick  in 

Transylvania. 

/ 

2.  HEMI-PRISMATlfc  SULPHUR. 

Red  Orpiment,  or  Ruby  Sulphur,  or  Hemi- Prismatic  Sulphur.    Jam. 
Orpiment.    Phil. 

Colour  aurora-red  in  several  shades,  but  which  differ  but 
little  from  each  other.  Streak  orange-yellow,  sometimes 
passing  into  aurora-red.  Lustre  resinous.  Sectile.  Hard- 
ness 1.5 — 2.0.  Sp.  gr.  3.55.  It  cleaves  parallel  to  the 
planes  of  a  rhombic  prism  of  105°  45'  and  74°  15'.  The 
terminal  plane  on  the  lateral  being  about  104°  6'. 


24  RESIN. 

Compound  varieties. — Massive.  Composition  granu- 
lar. Cross  fracture  conchoidal,  with  a  splendent  lustre. 

It  appears  before  the  blow-pipe  like  the  preceding  species. 
It  consists  of        Sulphur,         31.00 
Arsenic,         69.00 

3.  PRISMATIC  SULPHUR. 

Prismatic  Sulphur.    Jam.     Sulphur.    Phil. 

Colour  several  shades  of  sulphur-yellow,  inclining  some- 
times to  red  or  green.  Streak  sulphur-yellow,  passing 
into  white.  Lustre  resinous.  Transparent... translucent 
on  the  edges.  Sectile!  Hardness  1.5 — 2.5.  Sp.  gr. 
2.07.  Primary  form  an  octahedron  with  a  rhombic  base. 

Compound  varieties.— Imbedded  globules.  Massive. 
Composition  granular,  often  impalpable,  strongly  coher- 
ent ;  sometimes  pulverulent. 

1.  Sulphur  burns  with  a  bluish  flame.     By  friction  it  ac- 
quires resinous  electricity.     It  is  insoluble  in  water,  but  unites 
readily  with  soda  or  potash. 

2.  It  is  found  principally  in  volcanic  districts,  and  often  oc- 
curs in  splendid  crystals.     Sometimes  it  is  produced  by  the 
decomposition  of  pyrites. 

3.  Prismatic  Sulphur  requires  to  be  purified,  either  by  melt- 
ing or  sublimation,  before  it  is  fit  to  be  an  object  of  commerce. 
It  is  used  in  the  manufacture  of  gun-powder,  sulphuric  acid, 
and  various  other  articles. 

CLASS  III.    RESIN  COAL. 

ORDER  I.     RESIN. 
GENUS  I.    MELICHRONE*-RESIN. 

H.=2.0— 2.5 
G.=1.4— 1.6 

1.  PYRAMIDAL  MELICHRONE-RESIN. 

Pyramidal  Honeystone.    Jam.    Mellite.    Phil. 

Colour  honey-yellow,  inclining  often  to  red  or  brown. 

*Froin  the  Greek,  signifying  the  colour  of  honey. 


RESIN.  ,      225 

Streak  white.  Lustre  resinous.  Transparent.. .translu- 
cent. Sectile.  Hardness  2.0— 2.5.  Sp.  gr.  1.59.  Crys- 
talizes  in  the  form  of  obtuse  octahedrons,  of  which  the 
common  base  is  a  square.  It  yields  to  mechanical  divis- 
ion parallel  to  all  its  planes,  but  not  with  brilliant  faces. 

It  loses  its  colour  and  transparency  in  the  flame  of  a  candle, 
and  is  soluble  in  nitric  acid.  Only  one  authenticated  locality, 
viz,  Arten  in  Thuringia. 

'  GENUS  II.    MINERAL-RESIN. 

H.=0.0— 2.5 
G.=0.8— 1.2 

I.  YELLOW  MINERAL-RESIN. 

Yellow  Mineral-Resin,  or  Amber.    Jam. 
Amber.    Phil.    C. 

Prevailing  colour  yellow,  passing  into  red,  brown  and 
white.  Streak  white.  Lustre  resinous.  Transparent... 
translucent.  Not  very  brittle.  Hardness  2.4 — 2.5.  Sp. 
gr.  1.08.  Resinous  electricity  produces  friction.  Cleav- 
age none.  Fracture  conchoidal.  Surface  uneven  and 
rough. 

1.  It  burns  with  a  yellow  flame,  giving  out  an  agreeable 
odour,  and  leaves  a  carbonaceous  residue.     It  is  soluble  in  al- 
cohol. 

2.  It  is  found  in  the  greatest  quantity  on  the  Prussian  coast 
on  the  Baltic.    Also  on  the  coasts  below  Amboj»,  N.  J. 

3.  It  is  cut  into  various  ornaments  and  works  of  art.     Con- 
siderable value  is  attached  to  large  transparent  specimens. 

2.  BLACK  MINERAL-RESIN. 

Black  Mineral  Resin.    Jam. 

Mineral  Oil.    Bitumen.     Mineral  Pitch.     Phil. 

Prevailing  colour  black,  but  passes  into  various  brown 
and  red  tints.  Aggregation  solid  or  fluid,  and  all  the  in- 
termediate stages.  Fluid  varieties  are  sometimes  per- 
fectly colourless.  Streak  commonly  unchanged.  Frac- 


226  RESIN. 

ture  conchoidal,  more  or  less  perfect,  uneven.  Translu* 
cent  on  the  edges.. .opake.  Some  fluid  varieties  transpa- 
rent. Sectile.  Malleable.  Elastic.  Bituminous  odour. 
Hardness  0.0 — 2.0.  Sp.  gr.  0.82,  brown  malleable  va- 
riety ;  1.07  black  and  slaggy  variety ;  1.16  hyacinth-red, 
slaggy  variety.  No  regular  form  or  cleavage.  Massive. 

1.  The  present  species  has  been  divided  into  two  distinct 
species,  viz :  Mineral  Oil  and  Mineral  Pitch.    They  differ, 
however,  only  in  their  state  of  aggregation,  and  there  is  a  per- 
fect transition  from  the  most  perfect  fluid  to  the  solid  varieties. 
Mineral  Pitch  has  been  divided  into  elastic  earthy  and  slag- 
gy.   Those  varieties  are  also  joined  by  transitions.    The 
fluid  variety,  called  Naptha,  consists  of 

Carbon,         82.20        87.60 
Hydrogen,      14.80        12.78 

2.  All  the  varieties  are  highly  inflammable,  and  burn  with 
a  white  flame  and  much  smoke. 

3.  The  fluid  varieties  ooze  out  of  several  rocks,  as  sand- 
stone, clay-slate  and  the  bituminous  carbonate  of  lime  rock. 
The  slaggy  varieties  are  met  with  in  the  form  of  nodules  in 
limestone,  in  agate  balls,  in  veins  with  hexahedral  Lead- 
glance.     Also  on  the  shores  of  the  Dead  Sea. 

Elastic  Bitumen,  or  Elastic  Mineral  Pitch,  has  been  found 
only  in  Castleton,  Derbyshire,  though  I  have  observed  indica- 
tions of  it  in  a  fibrous  limestone  from  the  vicinity  of  Munroe, 
Ct. 

4.  The  different  varieties  allow  of  considerable  application 
for  illumination,  for  fuel,  in  fire-works,  in  the  manufacture  of 
varnish,  of  black  sealing  wax,  and  other  purposes. 

3.  REUNITE. 

Rttinite.    Jam. 
Retinasphalt.    Phil. 

Colour  green,  yellow,  red,  brown,  sometimes  in  striped 
delineation.  Lustre  resinous.  Semi-transparent.. .opake. 
Hardness  1.5—2.0.  Sp.  gr.  1.13, 

1.  It  takes  fire  in  the  flame  of  a  candle,  melts  and  burns 
with  a  particular  odor.  It  is  partly  soluble  in  alcohol,  leav- 
ing behind  an  unctuous  residue. 


COAL.  227 

It  consists  of    Vegetable  resin,  55. 

Bitumen  or  Asphalt,  42. 

Earthy  matter,  3. 

2.  It  has  been  found  in  the  beds  of  earthy-brown  coal, 
near  Halle,  on  the  Saale. 

ORDER  II.     COAL. 
GENUS  I.    MINERAL-COAL. 

H.=1.0— 2.5 
G.=1.2— 1.5 

1.  BITUMINOUS  MINERAL-COAL. 

Brown  Coal,  (excepting  Alum-Earth.)    Black  Coal    Jam. 

Black  Coal.    Common  Coal.     Cannel  Coal.    Jet-Brown  Coal.  Phil, 

Colour  black  or  brown,  passing  on  earthy  varieties  into 
grayish  tints.  Streak  unchanged,  except  that  it  some- 
times becomes  shining.  Opake.  Lustre  resinous,  more 
or  less  distinct.  Sectile  in  different  degrees.  Hardness 
1.0 — 2.5.  Sp.gr.  1.22,  moor  coal;  1.27,  common  brown 
coal;  1.27,  black  coal  from  Newcastle ;  1.32,  common 
brown  coal  from  Stiria;  1.43,  cannel  coal  from  Wigan, 
Lancashire. 

Compound  varieties. — Massive.  Composition  lamel- 
lar ;  faces  of  composition  smooth  and  even.  Texture 
granular,  often  impalpable,  and  then  the  fracture  is  un- 
even or  flat  conchoidal.  There  are  some  varieties  which 
have  a  loose  friable  texture. 

1.  Several  varieties  are  included  in  the  present  species,  as 
slate  coal,  foliated  coal,  coarse  coal,  cannel  coal,  pitch  coal, 
and  earthy  coal    All  these  varieties  are  joined  by  almost  im- 
perceptible gradations.    They  all  are  more  or  less  easily  in- 
flammable, and  burn  with  flame  and   a  bituminous  odour. 
Some  of  the  varieties  become  soft  and  coke  when  kindled. 
They  leave  a  more  or  less  earthy  residue. 

2.  Bituminous  Mineral-coal  is  very  generally  distributed, 


228  COAL* 

and  the  important  uses  to  which  it  is  applied  are  well  known. 
Deposits  of  it  are  found  in  Virginia,  Ohio  and  Pennsylvania. 

3.  Coal  is  probably  always  produced  from  vegetables.  The 
opinion  is  rendered  at  least  plausible,  from  the  fact  that  in 
the  vicinity  of  most  coal-beds  vegetables  are  preserved  in  the 
rocks,  sometimes  in  immense  quantities. 

2.  NON-BITUMINOUS  MINERAL-COAL. 
Glance  Coal.    Jam. 
Mineral  Carbon.    Mineral  Charcoal.    Anthracite.   Blind  Coal.  Phil. 

Colour  black  or  iron-black,  sometimes  inclining  to 
grayish-black.  Screak  unchanged.  Opake.  Lustre  im- 
perfect metallic.  Fracture  conchoidal.  No  regular  form 
or  structure.  Not  very  brittle.  Hardness  2.0 — 2.5. 
Sp.  gr.  1.40—1.48. 

Compound  varieties. — Massive.  Composition  lamel- 
lar, impalpable.  Some  varieties  are  vesicular,  others  are 
divided  into  columnar  masses,  meeting  in  rough  faces. 

1.  The  present  species  contains  the  following  varieties, 
viz  :  Conchoidal  and  Slaty  Glance-coal,  both  ofwhich  are  de- 
signated by1  the  name  of  Anthracite. 

2.  The  varieties  do  not  contain  any  bitumen,  but  consist  al- 
most wholly  of  carbon,  occasionally  mixed  with  variable  pro- 
portions of  oxide  of  iron,  silex  and  alumine.     It  is  frequently 
disseminated  in  quartz  crystals. 

3.  The  most  interesting  deposits  of  Anthracite  are  those  of 
Wilkesbarre  and  Carbondale,  Pa.    The  coal  region  of  Penn- 
sylvania is  quite  extensive,  and  numerous  beds  of  coal  have 
been  discovered  on  the  Lehigh,  Susquehannah  and  Schuylkill 
rivers.    The  deposits  of  Anthracite  at  Worcester,  Mass.,  and 
Portsmouth,  R.  I.,  differ  much  in  their  characters  from  the 
Lehigh  and  Wilkesbarre  anthracite.    The  coal  of  the  two  for- 
mer localities  is  much  less  combustible,  and  of  course  less  va- 
luable. 


APPENDIX  I. 

The  following  minerals  comprise  those  which  are  rare. 
The  greater  part  are  proposed  species,  which  are  not 
fully  established. 

AESCHINITE.    Brooke. 

Colour   brownish-yellow.       Hardness  between  apa- 
tite and  feldspar.     Sp.  gr.  5.14.     Resembles  gadolinite. 
It  is  found  in  Siberia. 

ALLOPHANE.    Jam.    Phil. 

Colour  blue,  green,  brown.  Transparent... translucent 
on  the  edges.  Lustre  vitreous,  inclining  to  resinous. 
Hardness  3.0.  Sp.  gr.  1.85 — 1.88. 

1.  Infusible  before  the  blow-pipe.     With  borax  it  melts  into 
a  transparent,  colourless  glass.    It  consists  of 

Alumine,  32.20 

Silex,  21.92 

Lime,  0.72 

Sulphate  of  lime,  0.51 

Carbonate  of  copper,  3.05 

Hydrate  of  iron,  2.27 

Water,  41.30 

2.  It  is  found  at  Saalfeld,  in  Thuringia. 

ARFVEDSONITE. 

Perilomous  rfugite-Spar.    Partsch. 

Hardness  5.0—6.0.  Sp.  gr.  3.3—3.4.  Inclination  of 
M  on  M  123°  55'. 

ARSENIET  OF  ANTIMONY.     Thomp. 

Colour  bluish-gray.  Lustre  metallic.  Sectile.  Tex- 
ture fine  granular.  Soft.  Sp.  gr.  6.13.  Massive. 

It  is  not  altered  by  exposure  to  air.  Before  the  blow- 
pipe it  fuses,  sublimes  in  white  smoke,  having  a  strong  ar- 
senical smell ;  leaving  scarcely  any  residue. 


230  APPENDIX  I. 

It  consists  of       Antimony,        46.61 
Arsenic,  38.50 

Loss,  14.88 

ARSENICAL  ANTIMONY-GLANCE. 

Colour  tin-white.     Lustre  metallic.     Hardness  2.0— 
3.0.     Sp.  gr.  6.2. 

ARSENICAL  BISMUTH. 

Colour  dark  hair-brown.      Lustre  resinous.     Soft. 
Heavy. 

ARSENIC-GLANCE. 

Colour  lead-gray.     Structure  compact.     Hardness  2.0. 
Sp.gr.  5.2—5.5. 

BABINGTONITE. 

Jlxotomous  dugite-Spar. 

Inclination  of  M  on  M'  155°  25'. 

BERTHIERITE. 

Sulphuret  of  Antimony  and  Iron. 

Colour  dark  steel-gray,  inclining  to  pinchbeck-brown. 
Lustre  metallic. 

1.  It  consists  of  4  atoms  of  sulphuret  of  Antimony,  and 
3  proto-sulphuret  of  Iron. 

2.  It  occurs  at  Chazelles,  in  Auvergne. 

BEUDANTITE.    Levy. 

.  Colour  black.  Lustre  somewhat  resinous ;  thin  frag- 
ments translucent.  Primitive  form  an  obtuse  rhomboid 
of  92°  30'. 

Composed  of  oxide  of  Lead  and  Iron.     Occurs  on  the 
banks  of  the  Rhine. 

BI-SELENIURET  OF  ZINC. 
Colour  gray. 

It  consists  of         Selenium,  49. 

Zinc,  24. 

Mercury,  19. 
Sulphur,  ;1.5 


APPENDIX  I.  231 

Jt  is  therefore  a  bi-seleniuret  of  Zinc  and  protosulphuret  of 
Mercury,  and  is  represented  by  the  following  formula :  zn. 
se.  4+Hgs. 

BISMUTH-BLENDE.    Breithaupht. 

Colour  reddish-brown.  Semi-transparent....  opake. 
Hardness  5.  Sp.  gr.  5.9.  Primary  form  a  rhombic  dode- 
cahedron. 

It  is  found  in  the  vicinity  of  Schneeburgh,  along  with 
Quartz,  the  oxide  of  and  native  Bismuth. 

BISMUTH  COBALT-ORE. 

Colour  intermediate  between  lead  and  steel-gray.  Lus- 
tre metallic,  and  glistening  or  glimmering.  Texture  in 
some  parts  radiated,  in  others  partly  stellular  and  partly 
parallel.  Scratches  fluor-spar,  but  this  degree  of  hardness 
may  be  owing  to  an  intermixture  of  fine  particles  of 
quartz.  Streak  dull,  unchanged. 

1.  Before  the  blow-pipe  on  charcoal  it  gives  out  white  va- 
pors of  arsenious  acid,  at  the  same  time  it  deposits  on  the 
coal  a  yellow  crust.    When  well  roasted  before  the  blow-pipe, 
and  then  mixed  with  glass  of  borax  and  melted,  it  communi- 
cates a  smalt-blue  colour. 

It  is  composed  of  Arsenic,  77.96 

Cobalt,  9.88 

Iron,  4.76 

Bismuth,  3.88 
Copper,  Nickel  and 

.  Sulphur,  3.41 

2.  It  occurs  at  Schneeberg. 

BLACK  COBALT  OCHRE. 

Colour  blueish  and  brownish-black,  blackish-brown. 
Streak  shining,  even  in  friable  varieties,  with  a  somewhat 
resinous  lustre.  Opake.  Sectile.  Soft;  sometimes 
passing  into  very  soft.  Sp.  gr.  2.20.  Forms  botryoidal, 
stalactitic.  Massive.  Composition  impalpable.  Frac- 
ture conchoidal..,very  fine  earthy. 


232  APPENDIX  I. 

Before  the  blow-pipe  it  gives  out  an  arsenical  smell  and 
colours  borax  smalt-blue.  It  consists  of  the  oxides  of  Cobalt 
and  Manganese. 

BOLTONITE. 

Bi-Silicate  of  Magnesia. 

Hardness  5.0 — 6.0.  Sp.  gr.  2.8 — 2.9.  Vitreous. 
Colour  grayish-white  and  yellowish-gray.  Streak  white. 
Composition  granular. 

BOTRYOGENE. 

Colour  hyacinth-red.  Hardness  2.0.  Sp.  gr.  2.03. 
Primary  form  a  right  rhombic  prism.  Inclination  of  M  on 
M'  120°. 

BRACHYTIPOUS  MANGANESE-ORE. 

Braunite.    Haidinger. 

Primary  form  octahedron  with  a  square  base.  Hard- 
ness 6.0—6.5.  Sp.  gr.  4.8. 

BREISLAKITE. 

Colour  reddish  or  chestnut-brown. 

1.  Before  the  blow-pipe  with  salt  of  phosphorus  a  green 
globule  is  obtained  in  the  oxidating  flame,  but  red  in  the  re- 
ducing flame. 

2.  It  occurs  in  delicate  capillary  crystals,  bent  and  grouped 
like  wool,  on  the  surface  of  cavities  in  lava,  at  Vesuvius  and 
Monticelli. 

BUSTAMITE.     Brongniart. 

Colour  light  gray,  greenish  or  reddish.  Hardness 
6.0 — 6.5.  Sp.  gr.  3.1 — 3.3.  Occurs  in  reniform 
masses. 

CALCAREOUS  HEAVY-SPAR.    Breithaupt. 

Sp.  gr.  4.0 — 4.2.     Effloresces. 

CARBONATE  OF  BISMUTH.  [ 

Colour  gray  and  brown.     Earthy.     Sp.  gr.  4.3. 
CHALKOSIDERITE.     Ullmann. 


APPENDIX  I.  235 

CHAMOISITE.    Berthier. 

Colour  dark  greenish-gray.  Earthy.  Sp.  gr.  3.4.  An 
impure  magnetic  Iron-ore  ? 

CHLOROPAL,    Phil. 

Colour  pistachio-green.  Opake,  or  only  translucent 
on  the  edges.  Massive.  Composition  impalpable,  earthy. 
Fracture  conchoidal,  passing  into  earthy.  Hardness  3.0 
— 4.0.  Sp.  gr.  2.0.  Fragile. 

1.  It  consists  of      Silex,  46. 

Oxide  of  iron,  35.30 
Manganese,      2. 
Alumina,  1. 

Water,  18. 

2.  It  is  remarkable  for  a  very  singular  magnetic  property. 
When  taken  from  its  original  repositories,  it  breaks  pretty 
readily  into  parallelepipeds,  the  upper  end  and  two  adjoining 
lateral  edges  having  the  opposite  magnetic  poles  from  the 
other  two  edges  and  the  lower  end. 

3.  It  occurs  in  Hungary,  and  is  often  called  Green  Iron- 
Earth.     Mohs. 

CHLOROPHEITE.     M'Culloch. 

Colour  dark-green  or  pistachio-green,  but  changing  to 
black  or  brown  on  exposure.  Brittle.  Hard.  Scratch- 
ed by  a  quill.  Sp.  gr.  2.02. 

1.  Before  the  blow-pipe  it  remains  unchanged,  either  in 
colour  or  transparency.    It  contains  silex,  iron  and  alumina. 

2.  It  occurs  in  trap  rocks. 

CHRESITE. 

Massive.  Composition  granular,  passing  into  impal- 
pable. Lustre  slightly  resinous. 

It.  melts  easily  before  the  blow-pipe  into  a  translucent 
globule.  It  dissolves  entirely  and  with  effervescence  in 
acids. 

CONDURRITE.    Phil. 

Colour  brownish-black.    Streak  dark  lead-gray,  pow- 
20* 


234  APPENDIX  I. 

der-black.     Brittle.     Hardness  5.0?     Composition   im- 
palpable. 

COTTUNITE.    (Chloride  of  Lead.) 
COUZERANiTE.     Charpentier. 

Colour  black.  Lustre  vitreous,  passing  into  resinous, 
Opake.  Scratches  glass,  but  not  quartz.  Structure  fo- 
liated. Primary  form  a  right  rhombic  prism. 

1.  Before  the  blow-pipe  it  fuses  into  a  white  enamel. 
It  consists  of        Silex,  52.37 

Alumine,  24.02 

Lime,  11.85 

Magnesia,  1.40 

Potash,  5.52 

Soda,  3.96 

2.  It  is  found  in  the  Pyrennes,  in  transition  limestone. 

CUMMINGTONITE. 

Far.  of  Anikophyllite,  ?    Karpholite  ? 

CUPREOUS  ANALCIME.    Jackson  and  Alger. 

Colour  verdigris-green;  paler  towards  the  interior  of 
the  crystals. 

CUPREOUS  MANGANESE. 

Colour  bluish-black.  Streak  unchanged.  Lustre  re- 
sinous. Opake.  Not  very  brittle.  Intermediate  be- 
tween semi-hard  and  soft.  Sp.  gr.  3.19 — 3.21.  Small 
reniform  and  botryoidal  groups.  Missive.  Composi- 
tion impalpable.  Fracture  imperfect  conchoidal. 

Before  the  blow-pipe  it  becomes  brown,  but  is  infusible, 
To  borax  and  salt  of  phosphorus  it  communicates  the  colour  of 
copper  and  manganese.  It  consists  of 

Black  oxide  of  manganese,     82. 
Brown  oxide  of  copper,          13.50 
Silex,  2. 

DIATOMOUS  ANTIMONY-PHYLLITE.    Breilhaupt. 

Hardness  1.0.  Sp.  gr.  4.0.  Lustre  pearly.  Colour 
grayish-white.  Translucent.  Feel  greasy. 


APPENDIX  I.  235 

DERMATINE. 

Colour  green  or  dark-brown.  Lustre  greasy.  Hard- 
ness 2.0.  Sp.  gr.  2.13.  Occurs  in  kidney-shaped  or 
globular  pieces.  Fracture  conchoidal.  Translucent. 
Saline. 

DEWEYLITE. 

Colour  white,  yellowish  and  greenish- white.  Trans- 
lucent. Streak  white.  Lustre  vitreous,  inclining  to 
resinous,  faint.  Easily  frangible,  especially  if  immersed 
in  water.  Hardness  3.0.  Sp.  gr.  2.2 — 2.3.  Composi- 
tion impalpable.  Surface  rough,  and  sometimes  drusy, 
exhibiting  small  mamillary  concretions.  Fracture  even, 
and  imperfectly  conchoidal. 

Before  the  blow-pipe  jt  decrepitates,  but  when  exposed 
carefully  to  the  flame,  small  fragments  melt  with  difficulty  into 
a  white  enamel  without  ebullition.     With  borax  it  forms  a  co- 
lourless transparent  glass. 
It  consists*  of        Silex,  40. 

Magnesia,        40. 
Water,  20.     Shepard. 

DYSLUITE. 

Primary  form  a  regular  octahedron.  Hardness  7.5, 
Sp,  gr.  4.35 — 4.36,  Colour  yellowish-brown.  Lustre 
semi-metallic. 

DYSODILE.     Cornier. 

Colour  greenish  and  yellowish,  passing  into  liver-brown. 
Streak  shining.  Fracture  earthy.  Soft.  Scratched  by 
a  quill.  Sp.  gr.  1.1 — 1.2. 

EDINGTONITE.    Haidinger. 

Colour  greenish-white.  In  small  crystals.  Hardness 
4.5.  Sp.  gr.  2.7. 

*  Nearly  the  same  results  were  obtained  by  myself.  The  specimen 
which  was  examined  contained  nearly  10  per  cent  more  of  water, 
which  I  attribute  to  the  fact  that  it  had  been  taken  from  its  bed  only 
a  few  days  previous  to  its  examination. 


236  APPENDIX  I. 

ERLANITE. 

Colour  greenish-gray,  usually  light.  Streak  white. 
Lustre  resinous.  Massive,  and  in  fine  granular  concretions, 
from  which  it  passes  into  compact.  Fracture  splintery 
or  even.  Hardness  between  apatite  and  feldspar.  Sp. 
gr.  3.0--3.1. 

1.  Before  the  blow-pipe  it  melts  into  a  transparent  bead ; 
with  borax  into  a  greenish  glass. 

It  consists  of        Silex,  53.16 

Alumine,  14.13 

Lime,  14.39 

Soda,  2.61 

Magnesia,  5.42 

Oxide  of  iron,      7.13 

2.  It  is  used  as  a  flux  in  the  iron  works  of  Erla,  in  the  Saxon 
Erzgebirge.    It  belongs  to  the  oldest  gneiss  formation.    Re- 
sembles gehlenite. 

FAHLUNJTE. 

Colour  olive-green  and  oil-green,  passing  into  yellow, 
brown  and  black.  Streak  grayish-white.  Feebly  trans- 
lucent on  the  edges... opake.  Lustre  vitreous.  Fracture 
conchoidal,  uneven,  splintery.  Scratches  glass.  Sp.  gr. 
2.61—2.66.  Reniform.  Massive. 

1.  Before  the  blowpipe  it  becomes  pale-gray,  and  melts  on 
its  thinnest  edges.     It  is  dissolved  in  glass  of  borax,  and  com- 
municates to  it  the  colour  produced  by  oxide  of  iron. 

It  consists  of  Silex,  46.79 

Alumine,  26.73 

Magnesia,  2.97 

Protoxide  of  iron,  5.01 
Oxide  of  manganese,  .43 
Water,  13.50  Hisinger. 

2.  It  occurs  at  Fahlun,  in  Sweden,  in  talcose  or  chloritic 
slate. 

FERRUGINOUS  PLATINA. 

Magnetic.    Less  malleable  than  Native  Platina.    Sp. 
r.  14.6—15,7. 


APPENDIX  I.  237 

FIBROLITE. 

Colour  white,  gray,  inclining  to  green,  Fracture  con- 
choidal.  Scratches  quartz.  Sp.  gr.  3.21.  Primary 
form  a  right  rhombic  prism,  with  angles  of  100°  and  80°. 

1.  It  is  composed  of    Alumine,    58. 
Silex,        38. 
*  2.  It  is  found  in  the  Carnatic,  accompanying  the  corundum. 

FIGURESTONE,  or  AGALM ATOLITE. 

Massive.  Composition  impalpable.  Fracture  coarse 
splintery,  imperfectly  slaty.  Colour  white,  gray,  green, 
yellow,  red,  brown ;  but  none  of  them  bright.  Transit 
cent,  in  most  cases  only  on  the  edges.  Soft.  Sp.  gr> 
2.81. 

1.  Infusible  before  the  blow-pipe.    It  consists  of 

Silex,  54.50 

Alumine,  34. 
Potash,          6.25 
Water,          4. 

2.  It  is  brought  from  China. 

GIBBSITE. 

Colour  white,  prevalent.  Streak  white.  Slightly 
translucent.  Lustre  resinous,  faint.  Hardness  3.5.  Sp. 
gr.  2.40.  Fracture  uneven.  Cleavage  none.  Reni- 
form,  botryoidal  and  stalaetitie  shapes.  Massive.  Com- 
position fine  granular,  passing  into  impalpable.  Earthy. 

1.  Before  the  blow-pipe  it  is  infusible.     It  consists  of 

Alumine,    64.8 
Water,       34.7 

2.  It  occurs  in  Richmond,  Mass.,  along  with  brown  hema- 
tite.   A  single  specimen  has  been  found  in  Lenox. 

GIESECKITE. 

Colour  olive-green,  gray,  brown.  Streak  uncoloured. 
Lustre  resinous,  faint.  Hardness  2.5 — 3.0.  Sp.  gr.  2.83,, 


238  APPENDIX  I. 

It  consists  of  Silex,  46.07 

Alumine,  33.82 

Magnesia,  1.20 
Black  oxide  of  iron,    3.35 

Manganese,  1.15 

Potash,  6.20 

Water,  4.88 

GLAUCOLITE.    Sokoloff. 

Colour  lavender-blue,  passing  into  green.  Lustre  vit- 
reous. Translucent  on  the  edges.  Hardness  5.0 — 6.0. 
Sp.gr.  2.71. 

1.  Before  the  blow-pipe  it  melts  with  difficulty,  but  is  soluble 
in  glass  of  borax. 

It  consists  of  Silex,  54  58 

Alumine,        29,77 
Potash,  4.57 

Lime,  11.18       , 

2.  It  occurs  near  Baikal,  in  Siberia,  in  compact  feldspar. 

GOKUMITE. 

Colour  light  yellowish-green.  Opake.  Scratched  by 
the  knife.  Sp.  gr.  3.74. 

1.  It  consists  of  Silex,  35.68 

Lime,  25.74 

Protoxide  of  iron,      34.46 
Alumine,  1,40 

Water,  0.60     TJiompson. 

2.  It  occurs  at  Go'kum  quarry,  Sweden.  . 

HALLOYITE. 

Colour  white,  or  slightly  blue.  Lustre  waxy.  Hard- 
ness 1.5—2.0.  Adheres  to  the  tongue. 

HARD  COBALT-PYRITES. 

Colour  dark  tin-white.  Lustre  metallic.  Hardness 
£.0—6.0.  Sp.  gr.  6.7—6.8. 

HATCHETINE. 

Colour  yellowish-white,  wax-yellow,  and  greenish-yel- 
Lustre  slightly  glistening  and  pearly.    When  in 


APPENDIX  I. 

flakes,  translucent.  Hardness  like  soft  tallow.  Very 
light.  Without  odor  or  elasticity.  Composition  some- 
times granular. 

1.  Fusible  below  212°  F.     Soluble  in  ether.     Smell  bitu- 
minous when  distilled  over  a  spirit  lamp. 

2.  It  occurs  filling  small  contemporaneous  veins,  lined  with 
calcareous  spar  and  small  crystals  of  quartz,  in  South  Wales. 

HEDYPHANE. 

Hardness  3.0 — 3.5.  Sp.  gr.  5.40.  Lustre  greasy. 
Colour  grayish-white.  Composition  granular,  impalpa- 
ble. 

HERDERITE.     Haidinger. 

Colour   yellow   or   greenish- white.      Streak    white, 
Translucent.      Lustre   vitreous,    inclining  to   resinous. 
Brittle.     Hardness  5.     Sp.  gr.  2.98. 
It  is  found  in  the  tin  mines  of  Saxonyl 

HERRENITE.    Del  Rio. 
Carbonate  of  Tellurium  and  Bi-carbonate  of  Nickel. 

HERSCHELITE. 

Primary  a  regular  hexagonal  prism.  Hardness  3.0 — 
3.5.  Sp.  gr.  2.1.  In  six-sided  prisms,  whose  terminal 
edges  are  replaced,  the  new  planes  inclining  to  the  base 
Tinder  angles  of  132° ;  bases  dull  and  curved. 

HISINGERITE.    Berselius. 

Colour  black.  Streak  greenish-gray.  Sectile.  Soft. 
Sp.  gr.  3.04.  Massive.  Fracture  earthy.  Cleavage 
in  one  direction. 

1.  If  heated  gently  it  becomes  magnetic ;  in  a  stronger  heat 
it  melts  into  a  dull,  opake,  black  globule.  With  borax  it 
yields  a  yellowish-green  glass. 

It  consists  of  Oxide  of  iron,  51.50 

.  Silex,  27.50 


240  APPENDIX  I. 

Alumina,  5.50 

Oxide  of  Manganese,      0.77 
Volatile  substance,        11.75 

2.  It  has  been  found  in  Sudermanland,  intermixed  with 
rhomboidal  Lime-haloide. 

HOPEITE. 

Prismatoidal  Orthoklase-Haloide.    Partsch. 

HUMBOLDTINE.    Mariano  De  Rivero. 

Colour  bright  yellow.  Soft,  yielding  to  the  nail.  Sp. 
gr.  1.3.  Acquires  resinous  electricity  by  friction. 

1.  On  ignited  charcoal  it  is  decomposed,  giving  out  a  veget- 
able odor,  while  the  remaining  oxide  of  iron  is  changed  into 
different  shades  of  yellow,  then  black,  and  at  last  red.     It  is 
insoluble  in  water  or  alcohol. 

It  consists  of     Protoxide  of  iron,    53.56 
Oxalic  acid,  46.14 

2.  It  is  found  in  coal  in  Bohemia. 

HUMITE. 

Colour  various  shades  of  yellow,  sometimes  almost 
white,  passing  into  reddish-brown.  Transparent... trans- 
lucent. Lustre  vitreous.  Brittle.  Hardness  6.5 — 7.0. 
Sp.  gr.  2.5.  Primary  form  a  right  rhombic  prism.  Inclin- 
ation of  M  on  M'120°. 

HYDRO-CARBON.     Scherer. 

Colour  white  or  yellowish-white.  Sp.  gr.  0.65.  Lus- 
tre pearly.  Crystals  acicular. 

HYDROUS-PHOSPHATE  OF  COPPER. 

Primary,  a  right  rhombic  prism.  Hardness  4.5 — 5.0. 
Sp.  gr.  4.2.  Inclination  of  M  on  M7  37°  30'. 

HYDRO-SILICITE.    Kuh. 

Colour  white,  without  lustre.  Feels  greasy.  Soft, 
and  translucent.  Does  not  adhere  to  the  tongue. 


APPENDIX  I.   /  241 

ILMENITE. 

Axotomous  Iron- Ore. 

Colour  black.  Lustre  metallic,  brilliant.  Fracture 
varies  from  uneven  to  conchoidal.  Cleavage  none. 
Scratches  glass.  Sp.  gr.  5.43.  Primary  form  a  right 
rhombic  prism  of  136°  30'.  The  terminal  edges  are  to 
the  lateral  as  17.11. 

It  is  found  at  Ilmen,  in  Siberia,  in  a  matrix  of  Albite, 
along  with  titaniferous  iron. 

IODIDE  OF  MERCURY.    Del  Rio. 

Resembles  dark-coloured  Cinnabar. 

IODIDE  OF  SILVER.      Vauqudin. 
IRID-OSMIUM.     Schwetzau. 

Colour  lead-gray.  Hardness  5.0 — 6.0.  Sp.  gr.  17.9 
— 18.5.  Crystalizes  in  low  six-sided  prisms. 

IRON  SINTER. 

Colour  yellowish  and  blackish-brown.  Brittle.  Lus- 
tre resinous.  Fracture  conchoidal.  Sp.  gr.  2.40.  Trans- 
parent...translucent  on  the  edges.  Not  very  brittle. 
Hardness  soft. 

1.  Before  the  blow-pipe  it  intumesces,  and  some  varieties 
emit  a  strong  arsenical  odor,  during  which  it  is  partially  vola- 
tilized.    It  consists  of 

Oxide  of  iron,  67.00  33.46 

Arsenic  acid,  0.00  26.06 

Sulphuric  acid,  8.00  10.75 

Protoxide  of  manganese,  0.00          0.59 

Water,  25.00  28.00 

2.  It  is  found  at  Saxony,  in  several  old  mines,  as  at  Frei- 
berg and  Schneeberg. 

KARPHOSIDERITE. 

Colour  yellowish-white.      Massive,   or  in  reniform 

masses.    Lustre  resinous.    Hardness  4.5.    Sp.  gr.  2.5, 

21 


242  APPENDIX  I. 

It  fuses  before  the  blow-pipe  on  charcoal  into  a  black 
globule ;  with  borax  and  salt  of  phosphorus  into  a  dark  sco- 
ria. Composed  of  oxide  of  manganese  and  zinc.  Green- 
land. 

KEROLITE. 

Hardness  2.0 — 2.5.  Sp.  gr.  2.0.  Lustre  vitreous, 
faint.  Colour  greenish-white. 

KONIGENE.    Levy. 

Primary  form  a  right  rhombic  prism.  Hardness  2.0. 
Colour  dark  emerald-green.  Crystals  barrel-shaped,  and 
closely  aggregated. 

KORNITE.    Breit. 
KUPFER1NDIG.    Breit. 

Colour  indigo-blue,  inclining  sometimes  to  blackish- 
blue.  Lustre  resinous.  Streak  resinous,  higher  than 
the  colour.  Opake.  Not  particularly  sectile.  Interme- 
diate between  soft  and  very  soft.  Sp.  gr.  3.80 — 3.82. 
Implanted  spheroidal  globular  shapes,  with  a  crystaline 
surface.  Massive.  Composition  impalpable.  Fracture 
flat  conchoidal,  uneven. 

1.  Before  the  blow-pipe  it  burns  before  it  is  red  hot  with  a 
blue  flame,  and  melts  into  a  globule,  and  emits  sparks.     It 
finally  yields  a  globule  of  copper. 

2.  It  occurs  in  Thuringia. 

LEELITE. 

Massive.  Lustre  and  translucency  like  horn.  Frac- 
ture splintery.  Sp.  gr.  2.71.  Clarke. 

It  consists  of       Silex,  75. 

Alumine,  22. 

Manganese  and  Water,    3.00 

MARMOLITE.    Muttall. 

Massive.  Cleavage  in  two  directions,  intersecting 
each  other  obliquely.  Lustre  pearly.  Colour  pale  green 


APPENDIX  I.  243 

or  gray.     Opake.    Brittle.     Easily  cut  with  a  knife. 

Sp.  gr.  2.47. 

It  is  considered  as  a  variety  of  serpentine,  and  occurs  in 
serpentine,  at  Hoboken,  N.  J.  and  at  the  Bare  Hills,  near 
Baltimore,  Md. 

MINERAL  HYDRO-CARBON. 

In  acicular  crystals.  Sp.  gr.  0.65  ?  Lustre  nacreous: 
Colour  yellowish-white. 

MOHSITE. 

Colour  iron-black.  Lustre  high  metallic.  Hardness 
6.0 — 6.5-  Crystals  small,  flat,  circular  tables,  with  al- 
ternate re-entering  and  salient  angles  on  their  edges, 
inclination  of  73°  43'. 

MOLYBDATE  OF  SILVER.    Breithaupt. 

Sp.  gr.  5.89.     Lustre  metallic.     Inflexible,  bladed 
masses  of  a  dark-gray  colour. 

MONAZITE. 

Colour  brick-red.  Lustre  vitreous.  Streak  flesh-red. 
Sp.  gr.  4.92. 

MONOPHANE. 

Colour  white.  Lustre  vitreous.  Hardness  below 
feldspar.  Sp.  gr.  2.15. 

MONTICELLITE. 

Colour  generally  yellowish,  but  sometimes  colourless 
and  transparent.  Primary  form  a  right  rhombic  prism  of 
1320  54.  Terminal  edges  to  the  lateral  as  1  to  1.046. 
In  muriatic  acid  the  surfaces  become  dull  and  coated  with 
a  yellowish  powder.  Hardness  between  apatite  and  feld- 
spar. Cleavage  none. 

It  occurs  at  Vesuvius. 


244  APPENDIX  I. 

MURCHISONITE. 

Colour  white,  with  a  slight  tinge  of  red.  Opake.  Ife 
possesses  cleavage  in  three  directions,  two  of  which  are  at 
right  angles  to  each  other,  like  the  two  principal  cleav- 
ages of  feldspar.  The  third  has  a  nacreous  appearance, 
and  is  as  easily  obtained  as  the  other  two,  and  is  perpen- 
dicular to  one  of  them,  and  inclines  to  the  other  at  an  an- 
gle of  106°  50' ;  so  that  the  solid  is  a  tetrahedron. 

1.  It  consists  of     Silex,  68.60 

Alumine,      16.60 
Potash,        14.80 

2.  It  is  found  at  Dawlish,  Eng.   It  is  sometimes  pulverulent 

NICKEL-GLANCE. 

Colour  like  Arsenical  Pyrites.     Hardness  5.5.     Sp* 
gr.  6.09.     Cleavage  parallel  to  the  faces  of  the  cube. 
NONTRONITE. 

Colour  pale  straw-yellow.  Soft.  Opake.  Unctuous 
and  tender.  In  onion-shaped  masses. 

OKENITE.     Kobel. 

Hardness  4.5 — 6.0.  In  almond-shaped  masses,  and 
allied  to  the  zeolites. 

OLIGOKLASE.     Breit. 
OSMELITE.    Breit. 

Hardness  5.5.  Sp.  gr.  2.70—2.83.  Resembles  the 
Kouphone-Spars. 

OSTRANITE. 

Hardness  6.5.  Sp.  gr.  4.3 — 4.4.  Lustre  vitreous* 
Colour  pale-brown.  Streak  pale-brown.  Fracture  une- 
ven. 

OXAHEVRITE. 

Colour  light  leek-green,  olive-green  and  reddish  brown; 


APPENDIX  I.  245 

Crystalizes  in  acute  octahedrons.     Cleavage  axotomous. 
Sp.gr.  2.21. 

1.  It  consists  of    Silex,  50.76 

Lime,  22.39 

Peroxide  of  iron,    3.39 
Alumine,  1.00 

2.  It  is  found  in  petrified  wood  near  Oxhaver,  in  Iceland. 

PEGANITE. 

Hardness  4.5.  Sp.  gr.  2.49.  Primary  form  a  right 
rhombic  prism.  M  on  M'  127°. 

PEKTOLITE.     Von  Kobell. 

Colour  grayish-white.  Lustre  pearly.  Surface  gen- 
erally dull.  Hardness  between  fluor  and  feldspar.  Sp. 
gr.  2.69.  It  occurs  in  spheroidal  masses  which  consist  of 
delicate  fibres  radiating  from  a  common  centre. 

1.  Before  the  blow-pipe  it  fuses  into  a  transparent  glass. 
It  is  composed  of      Silex,  51.30 

Lime,  33.77 

Soda,  8.26 

Potash,  1.57 

Water,  8.89 

Its  formula  is  4  C  S  2+3  K  5  Sz+6  Ag* 

2.  It  occurs  in  a  deposit  of  manganese  and  clay. 

PERIKLIN. 

Heterotomous  Feldspar.    Partsch. 

Hardness  6.0.  Sp.  gr.  2.54.  Primary  form  a  doubly 
oblique  prism.  P  on  M  93°  19'.  M  on  T  114°  45'. 

PETROSILEX,  (of  Sahlbtrg.) 

Colour  deep  flesh-red.  Transparent.  Compact.  Frac- 
ture fine  grained. 

PHASTIM.    Breit. 

PICOTITE.    Charptntier. 
21* 


246  APPENDIX  I. 

PICROLITE. 

Colour  leek-green,  passing  into  yellow.  Streak  shin- 
ing. Translucent  on  the  edges.  Hardness  3.0 — 6.0. 

It  consists  of       Silex,  40.04 

Magnesia,  38.80 

Water,  9.08 

Protox.  of  iron,        8.28 
Carbonic  acid,         4.70 

Colours  the  glass  of  borax  green  when  hot.  It  disappears 
when  cold.  It  occurs  in  veins  and  beds  in  iron  ore  in  the 
Faberg,  in  Sweden. 

PICROSMINE.    Haidinger. 

Colour  greenish- white.  Streak  white,  dull.  Translu- 
cent on  the  edges... opake.  Very  sectile.  Hardness  2.5 — 
3.0.  Sp.  gr.  2.66. 

1.  Before  the  blow-pipe  it  is  infusible.  Resembles  asbestus. 
It  gives  a  transparent  glass  with  borax,  and  is  soluble  in  heat- 
ed acids  with  the  exception  of  a  black  powder. 

It  consists  of     Silex,  10.43 

Alumine,  3.59 

Protoxide  of  cerium,         13.92 
Protoxide  of  iron,  6.08 

Yttria, 

*  Lime,  1.81 

Protoxide  of  manganese,    1.39 
Water,  26.50 

Carbon,  31.41 

2.  It  is  found  hear  Fahlun,  in  Sweden,  in  granite. 

PINGUITE.    Breit. 

Hardness .1.0.  Sp.  gr.  2.31.  Resembles  green  iron- 
earth. 

PINITE. 

Colour  blackish-green.. .greenish-gray.  Streak  unco- 
loured.  Feebly  translucent  on  the  edges.  Sectile.  Hard- 
ness 2.0—2.5.  Sp.  gr.  2,78. 


APPENDIX  I.  247 

1.  Before  the  blow-pipe  it  melts  in  thin  splinters  imperfect- 
ly. It  consists  of 

Silex,  55.96 

Alumine,  25.48 

Potash,  7.89 

Oxide  of  iron,        5.51 
Magnesia,  3.76 

Water,  1.41 

It  occurs  in  mica  slate  and  other  primitive  rocks. 
'    2.  It  is  found  at  Haddam,  Ct  Chester,  Mass,  and  Charles* 
ton,  N.  H. 

POLYHASITE. 

Hardness  2.5.  Sp.  gr.  6.2.  Colour  iron-black.  Lus- 
tre splendent.  Primary  form  a  hexagonal  prism. 

FOLYMIGNITE.    Berzelius. 
(Which  signifies  multiplicity  of  elements.) 

Colour  black.  Lustre  metallic.  Crystalizes  in  small 
rectangular  prisms. 

It  consists  of  the  oxides  of  titanium,  iron,  manganese,  tin, 
cerium,  and  of  the  earths  zirconia,  yttria,  time,  magnesia  and 
silex,  and  the  alkali  potash. 

POLYSPHJIRITE. 

Hardness  3.0.  Sp.  gr.  5.80.  Lustre  greasy.  Colour 
clove-brown  and  yellowish-gray.  In  rounded  balls  made 
up  of  concentric  layers. 

POONAHALITE 

Hardness  5.0 — 5.5.  Primary  form  a  right  rhombic 
prism.  Inclination  of  M  on  M'  92°  20'. 

PRISMATOIDAL  BISMUTH  GLANCE.     WehrU. 

Hardness  2.4.     Sp.  gr.  7.8.     Crystals  prismatic. 

PYRALLOLITE. 

Colour  white,  greenish-white.  Lustre  resinous.  Trans- 
lucent on  the  edges... opake.  Massive.  Composition 
granular.  Fracture  earthy.  Hardness  3.5—4.0.  Sp. 


24S  APPENDIX  I. 

gr.  2.55 — 2.60.      Powder  phosphoresces  with  a  bluish 
light. 

1.  Before  the  blow-pipe  it  first  becomes  black  then  white, 
and  finally  inturaesces  and  melts  on  the  edges. 

It  consists  of       Silex,  56.62 

Magnesia,  23.38 

Alumine,  3.38 

Lime,  5.58 

Oxide  of  iron,  0.99 

Protox.  manganese,  0.99 

Water,  3.58 

2.  It  occurs  at  Pargas,  in  Finland. 

PYRORTHITE. 

Colour  brownish-black,  if  decayed  yellowish-brown. 
Streak  brownish-black.  Lustre  resinous.  Opake.  Is 
scratched  by  carbonate  of  lime.  Sp.  gr.  2.19.  Massive. 

If  gently  heated  on  one  side  it  takes  fire  and  burns  without 
flame  or  smoke,  after  which  it  becomes  white  and  melts  into  a 
black  enamel. 

PYROLUSITE. 

Prismatic  Manganese- Ore.    Haidinger. 

Hardness  2.0 — 2.5.  Sp.  gr.  4.94.  Primary  form 
a  right  rhombic  prism.  Inclination  of  M  on  M'  93°  40' 

PYROMORPHITE. 
Rhombohedral  Lead-Baryte.     M. 

RADIOLITE.    Brevig. 

Hardness  above  4.0.  Sp.  gr.  2.2.  Colour  white. 
Lustre  silky.  Massive,  with  a  radiating  fracture. 

RUBELLAN. 

Colour  brownish-red.  Brittle.  Hardness  3.0.  Lustre 
vitreous,  inclining  to  resinous. 

SAPPARITE.    Schlotheim. 

Colour  pale  berlin-blue.  Streak  grayish-white.  Hard- 
ness 4.0.  Lustre  vitreous. 


APPENDIX  I.  249 

SAPHIRIN.    Stromeyer. 

Colour  sapphire-blue.  Streak  white.  Translucent, 
Lustre  vitreous.  Hardness  above  7.0.  Sp.  gr.  3.4. 

SCHEERERITE.    Stromeyer. 

Colour  whitish.  Lustre  pearly.  Very  friable.  Ra- 
ther heavier  than  water.  In  loosely  aggregated  grains 
and  scales. 

SELENIURET  OF  LEAD  AND  COBALT. 

Resembles  Galena.     Fracture  granular. 

SELENIURET  OF  LEAD  AND  COPPER. 

Fracture  granular.     Colour  lead-gray. 

SELENIURET  OF  LEAD  AND  MERCURY.    Rose. 

Sp.   gr.  7.8. 

SERPENTINE. 

Colour  dark  blackish  and  leek-green.  Seldom  lighter 
shades  of  oil-green  and  siskin-green,  and  none  of  them 
bright.  Also  brown  and  gray,  yellowish  gray.  Lustre 
resinous.  Indistinct,  low  degrees  of  intensity.  Streak 
white.  Translucent... opake.  Sectile.  Hardness  3.0. 
Sp.  gr.  2.50.  ' 

Compound  varieties. — Massive.  Composition  granu- 
lar, passing  into  impalpable.  Varieties  of  this  kind  pre- 
sent red,  brown,  black,  yellow  and  gray  colours,  in  veined, 
spotted  and  other  delineated  forms.  Regular  forms  have 
been  observed  in  the  blackish-green  and  yellowish-green 
varieties,  which  belong  to  the  prismatic  system.  Serpen- 
tine is  usually  divided  into  two  kinds,  the  common  and 
precious.  The  latter  presents  a  splintery  conchoidal 
fracture,  a  degree  of  translucency,  and  a  superior  hard- 
ness. 


250  APPENDIX  r. 

1.  It  consists  of  Silex,  42.50 

Magnesia,  38.63 

Alumine,  1.00 

Oxide  of  iron,  1.50 

Oxide  of  manganese,  0.52 
Oxide  of  chrome,  0.25 
Lime,  0.25 

Water,  15.20    John. 

2.  Serpentine  forms  mountain  masses  and  beds  in  primitive 
rocks.     It  is  found  in  Newfane,  Vt.,  Cummington,  Middle- 
field  and  Chester,  Mass.,  and  at  the  Bare  Hills,  near  Balti- 
more, Md.  ;,_ 

SILLIMANITE. 

Hardness  7.5 — 8.0.  Sp.  gr.  3.2.  Primary  form  an 
oblique  rhombic  prism,  oblique  from  an  obtuse  edge.  M 
on  M'  90°  30'.  Cleavage  brilliant,  parallel  to  the  longer 
diagonal. 

SORD AWALLITE.    Jfordenskiold. 

Colour  greenish  or  grayish-black.  Lustre  vitreous. 
Massive.  Hardness  5.0 — 6.0.  Sp.  gr.  2.53.  Fracture 
conchoidal. 

STERNBERGITE. 

Colour  dark  pinchbeck-brown,  rather  darker  than  mag- 
netic pyrites.  Lustre  metallic.  Streak  black.  Sectile. 
Tarnishes  Violet-blue.  Thin  laminae  perfectly  flexible. 
Hardness  1.0—1.5.  Sp.  gr.  4.21. 

1 .  Before  the  blow-pipe  it  burns,  giving  off  at  the  same 
time  the  odor  of  sulphureous  acid.    The  globule  which  re- 
mains is  coated  with  silver,  and  is  obedient  to  the  magnet. 
It  is  composed  of  the  sulphuret  of  silver  and  iron. 

2.  It  is  found  at  Jouchimsthal,  in  Bohemia. 

SULPHURET  OF  SILVER  AND  COPPER.    Phil 

Colour  blackish  lead-gray.  Lustre  metallic.  Soft, 
Sp.  gr.  6.25.  Massive,  Composition  impalpable. 


APPENDIX  I.  251 

TAUTOLITE.    Breithaupt. 

Colour  velvet-black.  Streak  gray.  Lustre  vitreous. 
Hardness  6.5— 7.0.  Sp.  gr.  3.86. 

Before  the  blow-pipe  it  melts  into  a  blackish  scoria,  which 
is  magnetic.  With  borax  it  melts  into  a  green  glass.  It 
consists  of  silex,  alumine,  and  the  oxides  of  iron  and  manga- 
nese. It  has  the  same  relation  to  Ciysolite  that  Ceylanite  has 
to  Spinelle. 

TELLURIC  BISMUTH.    Berselius. 
Colour    silver-white.      Lustre   metallic.      Massive. 
Sometimes  broad  foliated. 

TEPHROITE.    Breithaupt. 

Colour  ash-gray.  Lustre  adamantine.  Hardness  5.0 
—6.0.  ,Sp.  gr.  4.1. 

TESSERALKIES.    Breithaupt. 

THENARDITE. 

Anhydrous  Sulphate  of  Soda. 

Primary  form  a  right  rhombic  prism.  Hardness  2.0 — 
2.5.  Sp.  gr.  2,73.  Inclination  of  M  on  M'  125°. 

THORITE. 
Colour  black.    Hardness  6.0.     Sp.  gr.  4.63. 

Infusible  before  the  blow-pipe.  Occurs  at  Brevig,  in  Nor- 
way, in  Sienite. 

TURNERITE. 

Pictite. 

Colour  yellowish.  Semi-transparent.  Hardness  4.5 
— 5.0.  Primary  form  an  oblique  rhombic  prism.  In- 
clination of  M  on  M'  96°  10'. 

VELVET-BLUE  COPPER. 

Colour  bright  smalt-blue,  Lustre  pearly.  In  small 
capillary  crystals, 


APPENDIX  I, 

VIGNITE. 

„& ;  j  Blue  Magnetic  Iron-  Ore. 

Colour  dark  greenish-blue.     Sp.  gr.  3.71. 

WAGNERITE. 

Hemi-Prismatic  Fluor- Haloide.    M. 

Primary  an  oblique  rhombic  prism.     Hardness  3.0 — 
3.5.     Sp.  gr.  3.1.    Inclination  of  M  on  M'  95°  25'.     T 
on  M  109°  20'.     Crystals  complicated,  but  resembling  in 
colour  and  lustre  the  Brazilian  Topaz. 
WILLEMITE,     Levy. 

Colour  white,  yellowish  or  reddish.  Translucent.  In 
small  rhomboidal  crystals. 

YTTRO-CERITE.    Berseliu*. 

Hardness  4.0 — 4.5.  Sp.  gr.  3.44.  Colour  violet- 
blue.  Massive.  Opake. 

ZINKENITE. 

Haidingerite.    Berthier. 
Berthierite.     Haidinger. 

Hardness  3.5.  Sp.  gr.  5.3.  Lustre  metallic.  Colour 
steel-gray.  Streak  unchanged. 

ZURLITE. 

Hardness  6.0.  Sp.  gr.  3.27.  Lustre  resinous.  Colour 
green,  passing  into  gray.  In  rectangular  four-sided 
tables. 


APPENDIX  II. 


Minerals  which  will  probably  never  form  distinct  species 
in  the  Mineral  System. 

ADHESIVE  SLATE. 

Adhesive  Slate.    Jam.    Phil. 

Colour  yellowish-gray,  passing  into  white  and  smoke- 
gray.  Streak  a  little  shining.  Feebly  translucent  on 
the  edges.  Sectile.  Adheres  strongly  to  the  tongue. 
Very  soft.  Sp.  gr.  2.08.  Massive.  Composition  im- 
palpable. Fracture  slaty.  Cross  fracture  even,  flat 
conchoidal. 

On  exposure  to  a  red  heat  it  becomes  brown.  It  absorbs 
water  rapidly,  but  does  not  fall  to  pieces. 

It  consists  of  Silex,                  66. 50  30.80 

Alumine,                7.00  0.00 

Magnesia,             1.50  28.00 

Lime,                    1.25  0.80 

Oxide  of  iron,        2.50  11.20 

Carbonic  acid,      0.00  27.00 

Water,                19.00  0.30 

ALUM-SLATE. 

Alum- Slate.    Jam.     Phil. 

Colour  intermediate  between  grayish  and  bluish-black. 
Streak  black,  acquires  some  lustre.  Opake.  Dull. 
Not  very  brittle.  Intermediate  between  semi-hard  and 
soft.  Sp.  gr.  2.33 — 2.58.  Kirwan.  Massive.  Some- 
ftimes  in  spheroidal  masses.  Composition  impalpable. 
Principal  fracture  slaty. 

Alum-Slate  bas  been  divided  into  two  kinds,  common  and 
shining.  Alum-Slate  is  closely  allied  to  Clay-Slate.  Some- 

22  - 


254  APPENDIX  II. 

times  when  exposed  to  the  fire  it  burns  and  becomes  bluish- 
gray.     It  is  found  in  Pownal,  Vt 

BITUMINOUS  SHALE. 
Bituminous  Shale.     Jam.    Phil. 

Colour  brownish-black  and  blackish-brown.  Streak 
shining,  with  a  resinous  lustre.  Opake.  Lustre  faintly 
glimmering.  Sectile.  Sp.  gr.  1.99.  Massive.  Com- 
position impalpable. 

According  to  Werner  it  is  clay-slate  with  a  small  quantity  of 
bitumen.  It  occurs  in  the  variety  of  coal  mines.  It  is  to  be 
distinguished  from  a  variety  of  clay-slate  which  is  coated  with 
plumbago. 

BOLE. 
Bole.    Jam.    Phil. 

Colour  brown,  yellow  and  red.  Streak  shining  and 
resinous.  Feebly  translucent  on  the  edges... opake. 
Faintly  glimmering.  Dull.  Rather  sectile.  Adheres 
to  the  tongue.  Soft.  Sp.  gr.  1.60.  Massive.  Com- 
position impalpable. 

If  thrown  into  water  it  emits  a  crackling  noise  and  falls  to 
powder.  It  occurs  disseminated  in  wacke,  trapp-tuff,  &c. 

COMMON  CLAY. 
Common  Clay.     Jam.     Phil. 

Colour  white,  gray,  brown,  red,  yellow,  £c.  Dull. 
Sometimes  spotted  and  variegated.  Massive  and  sectile. 
Streak  shining.  Adheres  to  the  tongue.  Feels  more  or 
less  greasy.  Soft.  Massive.  Composition  impalpable. 

Common  clay  has  been  divided  into  loam,  potter's  day* 
variegated  day  and  slate  day.  The  appropriate  varieties 
of  clay  are  of  various  important  applications  in  pottery,  in 
manufacturing  stone  ware,  porcelain,  &c.  &c. 

DRAWING  SLATE,  or  BLACK  CHALK. 

Colour  intermediate  between  grayish  and  bluish-black. 


APPENDIX  II.  255 

Streak  unchanged.  Soils  more  or  less,  and  writes. 
Opake.  Sectile.  Adheres  to  the  tongue.  Soft.  Sp. 
gr.  2.11.  Massive.  Composition  impalpable. 

1.  Exposed  to  the  fire  it  loses  its  black  colour,  and  becomes 
reddish-gray. 

It  consists  of        Silex,  64.50 

Alumina,  11.26 

Oxide  of  iron,      2.75 
Carbon,  11.00 

Water,  7-50 

2.  It  occurs  in  rocks  of  clay-slate,  and  is  nearly  allied  to 
clay  and  alum-slate.     The  finest  varieties  come  from  Italy, 
Spain  and  France. 

FULLER'S  EARTH. 

Colour  green,  gray,  white.  Streak  shining,  resinous. 
Dull.  Feebly  translucent  on  the  edges...opake.  Frac- 
ture uneven  and  splintery.  Earthy.  Sectile.  Adheres 
but  feebly  to  the  tongue,  or  not  at  all,  and  is  very  soft. 
Sp.  gr.  1.81. 

If  thrown  into  water  it  falls  to  pieces,  and  forms  a  paste 
which  is  not  plastic.  It  absorbs  oil  and  fat ;  hence  it  is  used 
for  cleansing  woollen  cloth. 

LITHOMARGE. 

Lithomarge.    Jam.     Phil. 

Colour  white,  pearl-gray,  lavender-blue,  flesh-red, 
ochre-yellow.  Streak  shining.  Opake.  Fracture  un- 
even ;  and  flat  conchoidal  in  the  large,  fine  earthy  in  the 
small.  Adheres  to  the  tongue.  Sectile.  Massive. 
Composition  impalpable.  Sp.  gr.  2.43. 

It  has  been  divided  into  two  kinds,  the  friable  and  solid 
Lithomarge.  It  does  not  fall  to  powder  when  thrown  into 
water,  and  hardens  when  exposed  to  a  strong  heat. 

MOUNTAIN  SOAP. 

k    Colour  light  brownish-black.     Streak  shining,  resin- 


256  APPENDIX  II. 

cms.  Opake.  Dull.  Sectile.  Does  not  soil,  but  writes- 
Adheres  strongly  to  the  tongue.  Feels  greasy  ;  is  very 
soft  and  light.  Massive.  Composition  impalpable. 
Fracture  fine  earthy. 

It  has  been  found  in  Poland.  A  mineral  agreeing  with  the 
character  of  mountain  soap  is  found  in  small  masses  in  granu- 
lar limestone,  in  Williamstown,  Mass. 

POLISHING  SLATE. 

Colour  yellowish-gray,  inclining  to  white  or  brown. 
Feels  fine,  but  meagre.  Adheres  but  little  to  the  tongue. 
Soft.  Friable.  Sp.  gr.  0.59.  Massive.  Composition 
impalpable.  ] 

1.  It  imbibes  water,  but  does  not  fall  to  pieces.     It  becomes 
red  when  burnt,  but  is  infusible. 

It  consists  of       Silex,  79. 

Alumina,  1. 

Lime,  1. 

Oxide  of  iron,  4. 

Water,  14. 

2.  It  is  supposed  to  have  been  formed  from  the  ashes  of 
burnt  coal 

TRIPOLI. 

Colour  gray,  more  particularly  yellowish  and  ash-gray. 
Opake.  Not  particularly  brittle.  Does  not  adhere  to 
the  tongue.  Feels  meagre.  Massive.  Composition  in> 
palpable.  Fracture  earthy*  Sp.  gr.  1.85. 

1.  It  imbibes  water,  which  softens  it.    It  consists  of 

Silex,  81.  90. 

Alumine, 

Oxide  of  iron,         8.  3. 

Sulphuric  acid,        3.50          0. 

Water,  5.  0. 

2.  It  is  a  fine  variety  of  quartz,  mixed  with  a  little  clay. 

UMBER. 

Colour    liver,  chestnut   and  dark    yellowish-brown. 


APPENDIX  II.  257 

Streak  a  little  shining.  Opake.  Dull.  Imperfectly 
sectile.  Adheres  strongly  to  the  tongue.  Does  not  soil, 
but  writes.  Feels  rough,  and  is  very  soft.  Sp.  gr.  2.20. 
Massive.  Composition  impalpable. 

It  imbibes  water  with  avidity,  and  emits  air  bubbles,  but 
does  not  become  soft.  It  is  used  by  painters  as  a  brown 
colour. 

WHET-SLATE. 

Colour  greenish-gray,  mountain,  asparagus,  oil-green. 
Streak  grayish-white.  Translucent  on  the  edges.  Soft. 
Fracture  fine,  splintery  in  the  small.  Sp.  gr.  2.72. 
Massive.  Composition  impalpable. 

Whet-slate  is  slaty  rock,  containing  a  great  proportion  of 
quartz,  in  which  the  component  particles  are  so  fine  as  to 
withdraw  themselves  from  observation.  It  occurs  in  beds,  in 
clay-slate.  It  is  used  as  a  grinding  material. 

YELLOW  EARTH. 

Colour  ochre-yellow.  Streak  faintly  shining.  Opake. 
Faintly  glimmering,  dull.  Sectile.  Soils  a  little,  and 
writes.  Soft  and  friable.  Fracture  fine,  earthy.  Sp. 
gr.  2.24.  Massive.  Composition  impalpable. 

If  thrown  into  water  it  falls  to  powder  and  emits  a  noise. 
If  burnt  it  becomes  red.  It  is  a  mixture  of  fine  sand,  oxide  of 
iron,  and  clay.  It  is  employed  as  a  coarse  colouring  material. 

22* 


INTRODUCTION 

TO   THE 

STUDY  QF  GEOLOGY. 


§  1.  Definition. 

Geology  is  the  science  which  explains  the  Structure  of 
the  Earth. 

This  science  consists  essentially  in  a  systematic  arrange- 
ment of  facts  concerning  the  structure  and  relative  position  of 
the  strata  which  compose  the  exterior  of  the  earth.  It  con- 
siders also  those  causes  which  have  had  an  agency  in  modify- 
ing and  changing  the  surface  of  the  earth,  and  endeavors  to 
fix  the  dates  when  particular  changes  occurred. 

§  2.  Foundation  of  Geology. 
The  foundation  on  which  Geology  rests  is  observation. 

It  is  impossible  from  the  nature  of  the  science  that  it  should 
be  otherwise.  Many  geologists,  even  after  they  have  made 
numerous  observations,  have  fallen  into  error.  The  cause  is 
perfectly  plain,  viz.  the  great  extent  of  the  earth,  compared 
with  the  limited  means  which  any  individual  can  enjoy  for  col- 
lecting facts ;  the  concealment  of  strata,  by  overlaying  depos- 
its, and  the  derangements  which  have  taken  place  since  their 
deposition  :  these  and  many  more  prevent  that  accuracy  o 
judgment  which  could  be  made  in  case  all  the  materials  were 
exposed  and  without  derangement. 

§  3.   Uses  of  Geology. 

The  uses  to  which  geology  may  be  applied  are  numerous 
and  important.  It  initiates  us  into  the  history  of  the  earliest 
created  beings.  It  confirms  the  records  of  creation  as  given 
by  inspiration,  both  as  it  regards  the  order  and  the  successive 
periods  of  events.  By  it  we  are  taught  that  useful  substances 


260  INTRODUCTION  TO  THE 

are  connected  in  a  certain  order  in  every  district  of  country  ; 
and  hence  are  to  be  sought  for  only  in  particular  associations. 
By  knowing  the  character  of  the  different  deposites,  the  agri- 
culturist may  be  aided  in  the  improvement  of  soils  worn  out, 
or  naturally  barren. 

§  4.  History  of  Geology. 

Geology  is  a  modern  science. .  Its  foundation  was  laid  by 
Lehman,  the  German,  about  the  middle  of  the  last  century. 
He  was  followed  by  Mitchell  and  Whitehurst  in  England,  and 
Werner  in  Saxony,  all  of  whom  have  left  monuments  of  their 
industry  and  ability.  The  latter  especially  has  given  charac- 
ter and  great  interest  to  this  department  of  science.  The 
name  of  Werner  always  brings  to  mind  that  of  Hutton,  from 
the  fact  that  they  respectively  advanced  and  supported  theo- 
ries diametrically  opposite  to  each  other.  Which  deserves 
the  meed  of  having  done  the  most  for  geology,  it  is  not  for 
partial  critics  to  say.  Hutton,  however,  aided  by  the  happy 
illustrations  of  a  Playfair,  seems  to  have  ultimately  triumphed, 
though  many  of  Werner's  views  are  as  unshaken  as  the  rocks 
of  his  own  country. 

Saussure,  Humboldt,  Kirwan,  De  Luc,  Dolomieu,  Pallas, 
Jameson  and  Du  Fond,  have  been  active  and  enlightened 
inquirers  after  geological  facts,  and  have  added  much  to 
complete  the  history  of  the  earth.  Cuvier  has  done  more 
than  all  his  predecessors  in  fixing  the  dates  of  remarkable 
events,  as  the  creation  and  the  deluge,  and  in  bringing  to 
light  remarkable  fossils  and  remains  of  animals  which  are  now- 
extinct.  Bakewell,  Brogniart,  Conybeare  and  Phillips,  and 
Buckland,  have  discovered  much  in  relation  to  the  age,  posi- 
tion and  contents  of  the  strata,  which  will  serve  to  fill  up  the 
outline  of  a  general  history  of  the  earth.  In  saying  what 
some  have  done  in  this  interesting  field  of  labor,  we  would  by 
no  means  undervalue  the  efforts  of  those  who  are  still  in  the 
field,  collecting  new  facts  and  correcting  the  errors  of  former 
observers.  It  is  a  science  which  is  eminently  progressive, 
and  it  will  be  a  long  time  before  materials  can  be  collected 
sufficient  to  form  a  well  proportioned  edifice. 


STUDY  OF  GEOLOGY.  261 

§  5.  Objects  which  Geology  considers. 
The  general  objects  which  geology  considers  are  the 
strata,  And  the  relative  position  they  occupy,  and  the 
minerals  and  fossils  which  they  embrace. 

In  mineralogy  the  objects  are  single  individuals.  In  geolo- 
gy the  masses  are  generally  mixed  and  always  compound. 
They  occupy  great  space,  but  differ  from  each  other  in  this 
respect.  They  also  differ  in  relative  position,  and  this  is  the 
most  prominent  feature  in  the  science.  Granite,  for  instance, 
is  never  found  resting  on  graywacke  or  chalk. 

§  6.  Method  of  Studying  Geology* 

The  only  method  of  studying  geology  is  to  form  an  ac- 
quaintance with  rocks  in  the  field,  in  their  natural  deposits, 
or  in  the  situations  which  they  now  occupy,  by  transposition 
or  displacement.  The  student  may  apply  the  mineralogical 
characters  from  books  to  hand-specimens  in  the  cabinet ;  but 
after  all,  the  rocks  or  strata  must  be  seen,  and  their  relative 
position  observed.  We  are  also  to  observe  what  minerals  or 
fossils  the  stratum  contains ;  the  inclination,  whether  it  is 
horizontal,  or  dips  to  the  horizon,  or  is  vertical,  and  how  eithei; 
of  these  positions  affects  the  strata  above.  The  thickness, 
extent,  &c.,  are  to  be  accurately  noticed. 

§  7.  Limits  of  Observation. 

The  observations  which  we  are  able  to  make,  are 
limited  to  what  is  termed  the  rind  of  the  earth. 

We  can  know  but  little  of  the  interior  structure.  But  the 
inequalities  of  its  surface  often  give  us  admission  to  a  consider- 
able depth. 

§  8,  Weight  of  the  Earth. 

The  earth  is  supposed  to  be  about  five  times  heavier  than  a 
mass  of  water  of  the  same  bulk.  As  the  gravity  of  the  exter- 
nal coat  is  only  about  two,  it  is  inferred  that  the  interior  is 
composed  of  metals  or  materials  more  dense  than  the  exterior* 


262  INTRODUCTION  TO  THE 

§  9.  Internal  Heat  of  the  Earth. 

From  experiments  which  have  been  made,  principally  by 
Cordier,  it  seems  to  be  established  that  the  temperature  di- 
minishes as  we  penetrate  into  the  earth,  until  we  are  below 
the  limit  of  solar  influence.  And  that  from  that  point  the 
temperature  increases  at  the  rate  of  about  one  degree  of  Fah- 
renheit for  every  fifty  feet.  The  ratio  of  increase  varies  in 
different  countries.  But  it  is  remarked  by  Prof.  Eaton,  that 
it  is  not  probable  that  this  ratio  of  increase  is  preserved  to  the 
centre  of  the  earth.* 

§  10.  External  Heat  of  the  Earth. 

Geology  seems  to  demonstrate  that  the  external  tempera- 
ture of  the  earth  has  diminished,  and  is  perhaps  still  diminish- 
ing. The  external  part  would  evidently  cool  most  rapidly, 
while  the  internal,  being  protected  by  the  external  crust,  would 
cool  more  slowly.  The  facts  in  relation  to  the  external  and 
internal  temperature  of  the  earth,  may  be  applied  to  a  certain 
extent  to  explain  the  difference  of  temperature  of  the  same 
parallels  of  latitude. 

§11.    Sources  of  Information  concerning  the  Internal 
Structure  of  the  Earth. 

The  structure  of  the  earth  is  revealed  by  the  obliquity  of 
strata,  by  deep  excavations,  by  rivers  and  water  courses,  by 
vallies  and  defiles,  by  precipices,  clefts,  Glides  and  avulsions. 
From  these  sources  of  information,  geologists  have  demon- 
strated a  great  degree  of  regularity  in  the  deposition  of  strata 
composing  the  earth's  surface.  The  earth,  therefore,  is  not 
an  exception  to  the  general  law  of  order  which  is  so  conspicu- 
ous in  the  mechanism  of  the  universe. 

§  12.  Searing  of  Geology  on  Revelation. 

In  speaking  of  the  bearing  of  geology  on  revelation,  it  is  to 
be  borne  in  mind  that  the  great  object  of  revelation  is  to  pre- 

*  The  Edin.  Rev.  vol.  52,  p.  49,  contains  some  valuable  remarks  on  this 
subject,  and  a  notice  of  observations  by  M.  Moyle,  which  show  grounds  of 
error  not  taken  into  consideration  by  Cordier. 


STUDY  OF  GEOLOGY.  263 

sent  to  fallen  man  the  relation  he  holds  to  his  Maker,  and  the 
rules  of  action  which  he  ought  to  observe,  together  with  the 
method  of  regaining  that  high  standing  as  a  moral  being 
which  he  once  possessed  j  hence  the  subject  of  revelation  is 
not  physical  truth,  and  hence,  too,  we  are  not  to  expect  that 
precision  of  language  which  a  book  on  philosophy  observes, 
where  physical  truths  are  taught.  In  the  Bible,  however, 
there  are  two  important  eras  mentioned,  viz :  the  creation  and 
deluge,  which  have  occasioned  among  philosophers  no  little 
contention.  But  it  is  no  less  true  than  agreeable  to  the 
Christian,  that  geology  confirms  revelation,  in  language  which 
cannot  be  gainsayed  by  the  sophistry  of  infidels,  or  set  aside 
by  the  cavilings  of  sceptics. 

In  the  first  place,  the  antiquity  of  the  earth  is  attested  by 
numerous  facts,  and  it  can  be  shown  that  this  antiquity  ex- 
tends back  only  to  a  limited  time.  In  the  second  place,  in  re- 
gard to  the  deluge,  we  have  indubitable  evidence  that  such  a 
catastrophe  once  happened.  The  marks  of  it  are  now  to  be 
seen  in  every  country.  The  agreement  of  geological  facts 
with  those  revealed  in  sacred  writ,  is  at  least  consolatory  to 
the  humble  inquirer  after  truth.  It  is  by  no  means  necessary, 
however,  that  such  a  coincidence  should  exist,  to  entitle  the 
scriptures  to  our  implicit  credence ;  for  they  carry  such  au- 
thority and  evidence  of  truth  on 'every  page,  that  the  assistance 
which  geology  renders  is  but  small  indeed. 

§  13.  Design  which  is  manifest  in  the  Arrangement  of 
the  Materials  of  the  Earth. 

There  is  evidence  of  design  in  the  arrangement  of  the 
.strata  composipg  the  crust  of  the  earth. 

The  obliquity  of  the  strata  and  the  provision  furnished  in 
the  machinery  of  nature  for  a  supply  of  water  by  rivers  and 
springs,  are  not  to  be  considered  as  accidental  effects,  or  as 
occurrences  by  which  no  end  was  to  be  accomplished,  or  one 
end  as  well  as  another.  We  have  undoubted  evidence  of  de- 
sign in  those  arrangements.  Again,  the  disintegration  of 
rocks  to  form  soils  for  the  support  of  vegetable  and  animal 
life,  is  a  circumstance  which  ought  not  to  be  passed  over. 


264  INTRODUCTION  TO  THE 

Many  more  facts  of  a  similar  character  might  be  mentioned, 
but  these  few  are  sufficient  to  show  that  geology  furnishes 
proofs  of  design  in  the  general  construction  of  the  earth. 

§  14.  Geological  Theory. 

A  geological  theory  should  be  a  deduction  from  geo- 
logical facts. 

It  has  been  remarked,  that  geology  is  founded  on  observa- 
tion ;  yet  it  is  proper  to  admit  theory  as  a  means  of  advancing 
its  interests.  And  so  long  as  conclusions  are  drawn  from 
facts,  or  are  formed  agreeably  to  the  inductive  method,  its 
conclusions  will  have  as  much  certainty  as  those  which  belong 
to  general  physics,  and  often  approximate  to  a  demonstration. 

CONSIDERATIONS  WHICH  RELATE  TO  THE 
STRATA. 

§  15.  Division  of  Strata. 

The  strata  have  been  variously  divided  by  different  geolo- 
gists. The  first  grand  division  worthy  of  notice  was  proposed 
by  the  German  Lehman.  The  lower  rocks  he  observed  were 
crystalline,  very  hard,  and  sometimes  slaty ;  they  were  also 
destitute  of  the  remains  of  animals.  These  rocks  he  denomi- 
nated Primary,  or  Primitive.  Resting  upon  these  he  observed 
another  class  of  rocks,  which  were  comparatively  soft,  earthy 
in  texture,  and  contained  the  remains  of  animals.  These 
he  called  Secondary,  for  plain  reasons.  This  division  was 
undoubtedly  of  great  use  in  the  infancy  of  the  science.  It 
served  to  stimulate  men  of  science  to  observe  attentively  the 
position  or  order  of  the  rocky  strata.  The  discoveries  which 
were  consequently  made,  rendered  it  necessary  to  make  a  more 
accurate  classification.  A  more  perfect  division  or  classifica- 
tion of  strata  is  as  follows  : 

1.  Primitive. 

2.  Transition. 

3.  Secondary. 

( a)  The  Lower  Secondary  Series. 

(b)  The  Upper  Secondary  Series, 


STUDY  OF  GEOLOGY*  265 

4.  Tertiary. 

5.  Volcanic  and  Basaltic. 

6.  Diluvial  and  Alluvial  Ground. 

This  arrangement  is  substantially  followed  by  a  majority  of 
the  geologists  of  the  present  day,  even  by  those  who  are  op- 
posed to  the  terms  primitive,  transition,  &c.,  proving  that  the 
classification  is  founded  in  nature. 

§  16.  General  Character  of  the  preceding  Classes, 

1.  Primitive  Rocks — Were  so  called  because  no  fossil  re- 
mains of  animals  or  vegetables,  nor  any  fragments  of  other 
rocks  being  found  in  them,  it  was  inferred  that  they  were  form- 
ed prior  to  the  creation  of  organic  beings.     The  rocks  of  this 
class  are  hard  crystaline,  and  occupy,  geologically,  the  lowest 
place  in  the  series. 

2.  Transition  Rocks.' — They  are  so  called  because  it  is 
supposed  that  the  earth,  during  their  deposition,  was  passing 
from  an  uninhabitable  to  a  habitable  state.     In  them  we  first 
observe  the  existence  of  the  remains  of  animals.     These  ani- 
mals form  the  first  link  in  the  scale  of  animated  beings. 
They  are  generally  less  crystaline  in  structure,  softer,  and  are 
composed  of  the  fragments  of  the  primitive  rocks.     As  they 
are  interposed  between  the  primitive  and  secondary,  they  fre- 
quently partake  of  the  character  belonging  to  both. 

3.  Secondary  Rocks. — This  series  is  divided  into  Lower 
and  Upper  Series. 

(a)  Lower  Series.    The  lower  series  are  almost  all  dis- 
tinctly stratified.    They  consist  of  sandstone,  soft  argillaceous 
slate,  called  shale,  and  beds  of  coal  and  iron-stone.     In  many 
of  the  lower  secondary  series  we  find  abundance  of  vegetable 
fossils,  as  ferns,  palms  and  reeds ;  while  the  rocks  in  the 
transition  class  abound  in  marine  animals.     This  change  in 
the  kind  of  fossil,  indicates  an  important  change  in  the  state 
of  the  globe. 

(b)  Upper  Series.    The  prevailing  rocks  in  this  division 
are  stratified  limestone,  with  beds  of  clay,  shale  and  sand- 
stone.    The  organic  remains  are  again  animals,  which  show 

23 


266  INTRODUCTION  TO  THE 

that  another  important  revolution  had  taken  place.  These 
animals,  however,  are  of  different  genera  and  species  from 
those  in  the  lower  rocks.  The  position,  too,  of  the  upper 
secondary  is  different  from  the  lower ;  the  former  resting  upon 
the  inclined  edge  of  the  latter  unconformably.  The  last  of 
the  upper  secondary  is  chalk,  a  rock  which  is  wanting  in 
America,  and  some  other  countries, 

4.  Tertiary  Strata — Comprise  the  regular  beds  that  have 
been  deposited  since  the  chalk  strata,  and  on  which  they  fre- 
quently repose.    These  strata  occupy  considerable  extent. 
They  are  the  last  regularly  formed  strata,  and  consist  mostly 
of  alternate  beds  of  sand  and  clay.    The  lower  series  contain 
numerous  marine  shells,  while  the  middle  and  upper  contain 
shells  allied  to  those  now  found  in  rivers  and  bays.    The  most 
remarkable  feature  of  this  formation  is,  that  some  of  the  de- 
posits contain  numerous  bones  of  quadrupeds  of  the  class 
Mammalia,  but  which  belong  to  species  now  extinct. 

5.  Volcanic  and  Basaltic  Rocks. — They  always  cover,  in 
an   irregular  manner,  the  rocks  of  the    preceding  classes. 
They  have  evidently  been  in  a  state  of  fusion,  and  some  have 
poured  from  the  rents  and  fissures  in  the  earth's  surface  in  a 
liquid  state.     In  some  instances,  in  cooling,  the  masses  have 
partially  crystalized,  forming  many-sided  columns  or  pillars  ; 
in  other  cases,  the  melted  matter  fills  vast  fissures,  called  by 
miners,  dykes. 

6.  Diluvial  and  Alluvial. — The  greater  part  cf  the  ground 
in  most  countries  is  covered  with  thick  beds  of  gravel,  sand, 
clay,  and  fragments  of  rock  or  loose  stones,  more  or  less 
rounded  by  attrition.     Frequently  these  masses  of  rock  have 
been  transported  a  great  distance.    They  indicate  the  action 
of  mighty  currents,  which  have  swept  over  the  face  of  the 
earth  with  an  overwhelming  power. 

§  16.  Distinguishing  Characters  of  the  preceding 
Classes  of  Rocks. 

The  different  rocks  and  strata,  except  the  primitive, 
are  distinguished  by  their  appropriate  organic  remains. 


STUDY  OF  GEOLOGY.  267 

This  declaration  is  perhaps  too  general  and  sweeping.  It 
may  be  that  in  some  instances  two  deposits  belonging  to  dif- 
ferent periods  may  embrace  similar  organic  remains ;  but 
there  are  boundaries  or  lines  which  may  be  drawn,  where  we 
can  say  that  above  or  below  it  such  and  such  organic  remains 
are  never  found,  and  it  would  be  as  useless  to  look  for  them  as 
for  coal  in  granite. 

§  .17.  The  Passing  of  one  Stratum  into  another. 

Strata  do  not  always  preserve  a  perfect  uniformity  or 
distinctness  throughout  their  several  courses,  but  fre- 
quently pass  into  each  other. 

Strata  sometimes  pass  into  each  other  in  a  remarkable  man- 
ner. Thus  mica  slate  passes  into  talcose  slate,  talcose  slate 
into  soapstone,  and  soapstone  into  serpentine.  Granite  passes 
into  gneiss,  and  sienite  into  a  coarse  mica  slate.  These  tran- 
sitions more  frequently  occur  among  the  primitive  strata  than 
the  others.  They  may  be  seen  throughout  the  primitive  re- 
gion of  New-England ;  so  that,  in  fact,  the  primitive  rocks 
might  be  considered  as  one  vast  stratum,  composed  of  alter- 
nating layers  of  granite,  gneiss,  mica  slate,  talcose  slate  and 
hornblende. 

§  18.  Inclination  of  the  Strata. 

The  strata  are  rarely  equally  inclined,  especially  in 
different  formations. 

The  position  of  the  primitive  strata  are  usually  nearly  verti- 
cal, and  very  commonly  seem  to  have  been  forced  through  the 
superincumbent  rocks,  and  hence  they  crown  the  summits  of 
the  highest  mountains. 

The  transition  appear  at  a  lower  level,  near  the  bases  or  on 
the  sides  of  mountains,  and  their  position  is  of  course  inclined. 
But  the  degree  of  inclination  varies  at  different  places,  and 
sometimes  near  their  edges  they  are  thrown  into  a  vertical 
position. 

The  secondary  approach  the  horizontal  position,  often  rest- 


268  INTRODUCTION  TO  THE 

ing  upon  the  inclined  edges  of  the  inferior  rocks.     The  coun- 
try they  occupy  is  generally  flat  and  level. 

CONSIDERATIONS  WHICH  RELATE  TO  VOLCA- 
NOES AND  EARTHQUAKES. 

§  19.  Seat  of  Volcanoes. 

Volcanic  action  is  seated  below  the  primitive  rocks.  Thus 
the  products  of  ancient  as  well  as  modern  volcanoes  are  analo- 
gous in  their  composition  to  the  oldest  granite,  sienite  and 
porphyry. 

§  20.  Kind  and  Quantity  of  Materials  which  Volcanoes 
throw  out. 

The  quantity  of  lava  and  other  substances  which  volcanoes 
throw  out  is  enormous.  It  is  said  by  Kircher  in  1660,  that 
the  ejections  of  Mount  JEtna  would,  if  collected,  form  a  mass 
twenty  times  as  large  as  the  mountain  itself.  And  in  a  few 
years  after,  in  1669,  the  same  mountain  was  covered  with  a 
fresh  current  of  lava,  eighty-four  square  miles.  And  again  in 
1775,  according  to  Dolomieu,  the  same  volcano  poured  out 
another  stream  of  lava  twelve  miles  in  length,  and  one  mile  and 
a  half  in  breadth,  and  two  hundred  feet  in  depth.  The  largest 
known  current  of  modern  lava  was  formed  by  a  volcano  in 
Iceland,  and  was  ejected  in  1783.  It  is  sixty  miles  in  length, 
and  twelve  broad. 

The  kinds  of  matter  thrown  out  by  different  volcanoes 
varies  at  different  times.  Thus  sometimes  appear  smoke, 
steam,  flame,  stones,  sand,  ashes,  mud  and  lava. 

When  a  volcano  breaks  out,  especially  if  in  a  new  situation, 
it  is  preceded  by  violent  earthquakes.  The  heated  ground 
swells  up  until  a  fissure  is  formed,  which  is  sometimes  of  vast 
extent.  Through  this  rent,  flame  and  smoke,  and  melted 
stones  are  ejected.  Hence  earthquakes  are  always  connected 
with  volcanic  action. 


'-"H1  "; 

STUDY  OF  GEOLOGY,  269 

§  21.  Cause  of  Volcanic  Action. 

Werner  supposed  that  volcanic  action  was  produced  by  the 
combustion  of  beds  of  coal.  This  supposition  is  abundantly 
disproved  by  the  fact  that  volcanic  action  is  far  below  the  coal 
deposits ;  and  if  it  were  not,  no  beds  of  coal  of  sufficient  ex- 
tent could  be  found  to  supply  combustible  matter  for  a  single 
capital  operation.  A  more  rational  theory  of  volcanic  action 
has  been  proposed,  which  is  founded  on  the  intense  chemical 
action  which  ensues  when  many  elementary  bodies  are  brought 
in  contact.  Or  it  may  be  remarked  that  galvanic  action  illus- 
trates very  perfectly  the  condition  under  which  volcanic  action 
may  take  place.  For  an  exposition  of  the  theory  of  volcanic 
action,  see  Bakewell's  Geology,  American  edition. 

§  22.  Conclusion. 

In  the  preceding  sketch  it  was  intended  to  present  only 
some  of  the  leading  and  prominent  features  of  geological 
science,  or  just  so  much  as  would  excite  inquiry  and  stimulate 
to  action  those  in  whose  hands  the  book  should  happen  to  fall. 
The  study  of  geology  is  one  of  increasing  interest  to  this 
country.  Its  resources  are  yet  to  be  developed,  and  much 
depends  on  scientific  geology.  If,  therefore,  the  few  geologi- 
cal facts  and  principles  which  this  slight  outline  contains  shall 
serve  to  create  a  taste  for  the  science,  or  prove  its  utility,  the 
object  of  the  author  will  be  accomplished. 


23* 


NOTES 

REFERRED  TO  IN  THE  INTRODUCTION  TO  MINERALOGY. 

NOTE  A. 

According  to  the  views  of  Prof.  Mobs,  a  primary  form  is  a  simple 
form,  from  which  other  simple  forms  are  derived,  and  is  denominated 
a  fundamental  form,  and  the  class  of  figures  derived  from  that  funda- 
mental form,  systems  of  crystalization.  These  systems  are  termed 
the  Tessular,  Pyramidal,  Prismatic,  Rhombohedral,  Hemi-prismatic, 
and  Tetarto-prismatic. 

The  tessular  system  embraces  the  regular  tetrahedron,  regular  octa- 
hedron, cube  and  rhombic  dodecahedron.  The  pyramidal  system 
contains  the  octahedron  with  a  square  base,  and  the  right  square 
prism.  The  prismatic  system  contains  the  rectangular  and  rhom- 
bic octahedron.  The  rhombobedral  system  includes  the  rhombo- 
hedron  and  the  regular  hexagonal  prism.  The  hemi-prismatic  in- 
cludes the  right  rhomboidral  and  the  oblique  rhombic  prisms. 
The  tetrato-prismatic  contains  the  doubly  oblique  prism.  This  dis- 
tinction is  so  far  important,  that  all  the  forms  which  a  mineral  as- 
sumes must  belong  to  the  same  system  of  crystalization.  For  in- 
stance, the  forms  belonging  to  the  tessular  system  produce  among 
themselves  various  combinations,  but  they  admit  into  them  no 
form  which  is  a  rhomboid,  or  a  four-sided  pyramid  with  a  square 
base,  or  an  oblique  four-sided  pyramid.  The  rhomboid  and  octahe- 
dron with  a  square  base,  and  the  octahedron  with  an  oblique  base,  are 
forms  which  cannot  by  any  means  be  derived  from  each  other. 
Hence  those  systems  of  crystalization  form  groups  which  are  alto- 
gether distinct  from  the  rest. 

NOTE  B. 

The  common  goniometer  consists  essentially  of  a  semi-circle  gradu- 
ated to  180°,  and  two  arms  moveable  on  a  common  centre.  To  use 
this  instrument,  the  arms  at  one  extremity  must  be  applied  accurately 
to  two  adjoining  planes;  the  number  of  degrees  which  the  arm  on 
the  opposite  side  of  its  centre  cuts  off,  indicates  the  angle  at  which 
the  planes  meet. 

The  reflecting  goniometer  is  an  instrument  much  more  complicated. 
It  consists  of  an  entire  circle,  divided  into  degrees  upon  its  edge,  and 
so  disposed  as  to  move  vertically  upon  an  horizontal  moveable  axis. 
The  axis  projects  on  both  sides  of  the  graduated  circular  plate.  On 
the  one  side  there  are  two  lesser  circles  or  wheels,  one  of  which 


272  NOTES. 

moves  the  axis  on1y,"and  the  other  the  graduated  circle  and  axis.  On 
the  opposite  side  the  axis  projects  for  the  purpose  of  attaching  the 
crystal  to  be  measured.  To  use  the  instrument,  it  must  first  be  ad- 
justed, which  is  effected  by  placing  it  on  a  small  stand  on  a  firm  table, 
of  such  an  elevation  as  to  permit  the  experimenter  to  steady  his  el- 
bows on  the  table,  while  his  eye  shall  not  be  above  the  axis  of  the 
instrument.  The  table  must  be  placed  before  a  common  window, 
with  the  wheel  moving  vertically  to  the  window,  and  from  six  to 
twelve  feet  from  it.  A  black  line  is  to  be  drawn  parallel  to  the  hori- 
zontal bars  of  the  window,,  between  it  and  the  floor.  The  crystal  is 
now  to  be  attached  to  the  axis  of  the  instrument  by  a  piece  of  wax. 
In  attaching  the  crystal,  the  edge  formed  by  the  meeting  of  the  planes 
whose  angle  we  wish  to  measure,  must  coincide  with  the  centre  of 
the  axis  of  the  instrument,  or  a  line  passing  through  the  axis.  This 
being  done,  we  are  to  observe  if  the  line  which  indicates  180°  upon, 
the  circle,  corresponds  with  a  line  marked  0  on  the  vernier,  and  also 
that  the  reflection  of  a  known  bar  of  the  window  is  seen  along  the 
black  line.  The  exterior  axis  is  now  to  be  turned  until  the  image  of 
the  bar  reflected  from  the  other  plane  is  seen  to  coincide  with  the 
same  line  below.  The  number  of  degrees  and  minutes  at  which  the 
planes  incline,  may  now  be  observed. 

The  instruments  which  are  here  partially  described,  are  both  of 
them  useful,  and  the  reflecting  goniometer  indispensable  to  the  stu- 
dent who  would  be  an  accomplished  mineralogist.  The  relative  ad- 
vantages of  each  become  evident  on  reflection,  and  do,  not  require  a 
particular  consideration. 

NOTE  Ct 

There  are  some  secondary  forms  which,  as  we  have  seen,  are  de- 
rived from  the  primary  by  certain  symmetrical  modifications  in  these 
cases.  We  shall  be  able,  in  general,  to  say  that  a  crystal  of  this  sort 
belongs  to  one  of  two  or  three  of  the  primary  forms.  For  instance, 
if  the  crystal  is  a  trapezoedron,  we  know  it  can  come  only  from  the 
cu&e,  the  regular  octahedron,  or  rhombic  dodecahedron  ;  if  a  pen- 
tagonal dodecahedron,  it  must  come  from  the  cube ;  if  a  dodecahe- 
dron with  scaline  triangular  faces,  it  can  come  only  from  the  rhom- 
boid. In  the  absence  of  cleavage,  the  student  will  occasionally  meet 
with  some  embarrassment..  In  this  case  it  will  be  best  to  obtain  seve- 
ral forms  of  the  mineral,  which  will  perhaps  enable  him  to  fix  upon 
the  primary  agreeably  to  symmetrical  changes,  as  noticed  in  §  50. 
Thus  if  the  crystal  is  a  cube,  that  must  be  the  primary  form  ;  or  a 
tetraedron,  regular  octahedron,  or  rhombic  dohecahedron — the  only 
forms  with  which  it  can  be  connected.  If  an  octahedron  with  a 
square  base,  it  must  be  identical  with  that,  or  the  right  square  prism  ; 
if  the  regular  hexagonal  prism,  that  must  be  the  primary,  or  it  is  de- 
rived from  the  rhomboid.  There  are  cases,  however,  wore  difficult 


NOTES.  273 

than  any  we  have  yet  noticed.  When,  for  instance,  all  the  primary 
planes  are  extinguished,  and  when  in  addition  to  this  many  of  them 
are  unduly  extended,  though  they  may  stHl  be  symmetrically  dis- 
posed. Some  experience,  aided  by  a  few  rules,  will  enable  the  stu- 
dent to  overcome  most  difficulties  which  occur.  When  the  secondary 
crystal  retains  some  portion  of  the  primary  planes,  we  should  in  that 
case  observe  whether  there  be  on  the  crystal  any  series  of  planes 
whose  edges  are  parallel  to  each  other.  If  such  is  the  fact,  we  should 
then  hold  the  crystal  in  such  a  manner,  that  the  series  of  parallel 
edges  may  be  vertical  or  upright ;  and  while  in  this  position,  we 
should  observe  whether  there  be  any  plane  at  right  angles  to  the  ver- 
tical planes.  If  on  examining  the  secondary  forms  of  crystals,  we 
meet  with  two  sets  of  parallel  planes,  either  of  which  held  upright, 
the  crystal  would  present  a  series  of  parallel  planes,  we  should  in 
that  case  endeavor  to  ascertain  whether  the  planes  belonging  to  one 
set  are  more  symmetrical  than  the  other  set.  If  so,  they  are  to  be 
made  the  vertical  series.  Jf  there  exist  a  series  of  vertical  planes  and 
a  horizontal  plane,  we  should  observe  whether  any  of  the  vertical 
planes  are  at  right  angles  to  each  other,  and  whether  there  be  any 
oblique  planes  lying  between  some  of  the  vertical  planes  and  the 
horizontal  planes. 

We  should  remark  the  equality  or  inequality  of  the  angle  at  which 
any  of  the  vertical  or  oblique  planes  incline  on  the  several  adjacent 
planes,  and  also  if  there  is  a  symmetrical  arrangement  of  the  vertical 
planes,  or  of  the  oblique  planes,  which  would  induce  us  to  refer  our 
crystal  to  any  particular  class  of  primary  forms.  If  the  crystal  is  con- 
tained within  any  series  of  vertical  planes,  and  is  terminated  by  a  single 
oblique  one,  the  crystal  may  belong  to  the  class  of  oblique  rhombic 
prisms,  doubly  oblique  prisms  or  rhomboids.  If  there  are  four  oblique 
planes  inclining  to  each  other  at  equal  angles,  the  crystal  may  belong 
to  the  class  of  square  prisms,  or  of  octahedrons  with  square  bases. 
If  there  are  four  oblique  planes,  each  of  which  inclines  on  two  adja- 
cent planes  at  unequal  angles,  the  crystal  probably  belongs  to  the 
class  of  right  rectangular,  right  rhombic  prisms,  or  octahedrons  with 
rectangular  or  rhombic  bases.  If  the  series  of  vertical  planes  are  six, 
nine,  twelve,  or  some  multiple  of  three,  and  if  there  be  a  single  hori- 
zontal plane,  the  crystal  may  belong  to  one  of  the  classes  of  right 
prisms,  rhomboids,  or  hexagonal  prisms.  If  there  be  three  oblique 
planes,  the  primary  is  a  rhomboid.  But  if  the  termination  consists 
of  six  oblique  and  equal  planes,  the  crystal  belongs  to  the  rhomboid 
or  hexagonal  prisms. 

The  most  difficult  forms  to  be  understood,  are  those  belonging  ta 
the  doubly  oblique  prisms.  These  can -only  be  learnt  by  cleavage, 
and  from  comparing  crystals  with  each  other,  and  with  tables  of 
modification.  See  Brooke,  p.  106, 211. 


274  NOTES. 

NOTE  D. 

(  The  importance  of  observing  the  appearance  of  surfaces  will  be- 
come evident  from  the  following  remarks.  They  will  be  made  under 
the  following  heads,  viz  -.Faces  of  crystalizalion— Faces  of  cleavage — 
Faces  of  composition,  and  Faces  of  fracture. 

The  most  interesting  faces  are  those  which  are  even,  since  they  are 
subject  to  a  constant  law.  These  are  always  faces  of  crystalization 
or  faces  of  cleavage.  The  different  qualities  of  even  faces  consist  in 
their  being  smooth,  or  in  being  provided  with  slight  elevations 
which  do  not  obscure  the  general  form  of  the  crystal,  or  interrupt  the 
continuity  of  faces.  Those  faces  which  are  not  perfectly  smooth 
may  be  striated,  rough  or  drusy.  The  slriae,  which  appear  on  faces  are 
produced  by  the  alternating  reappearance  of  the  faces  of  those  simple 
forms  which  are  contained  in  the  compound  ones,  and  are  always 
parallel  to  the  edges  of  combination,  or  between  the  simple  and 
compound  forms.  In  rhombohedral  quartz,  the  alternate  lateral  faces 
are  striated  longitudinally.  Hexahedral  iron-pyrites  are  streaked, 
the  stria  being  parallel  on  parallel  faces.  In  beryl  the  faces  are  stri- 
ated longitudinally.  Faces  which  are  homologous  show  similar  ap- 
pearances on  their  faces,  which  circumstance  furnishes  a  character  by 
which  they  may  be  known. 

Faces  which  are  termed  rough  and  drusy,  arise  from  projecting  solid 
angles  instead  of  edges.  Those  faces  differ  principally  in  the  size  of 
the  elevations.  In  octahedral  fluor-haloide,  the  octahedral  crystals 
seem  to  be  composed  of  cubic  crystals,  the  faces  of  which  are  per- 
pendicular to  each  other;  and  a  plane  passing  through  their  solid  an- 
gles is  parallel  to  the  faces  of  the  octahedron.  Those  particles 
which  thus  project  are  not  to  be  considered  as  compound  ;  they  ra- 
ther indicate  the  gradual  formation  of  crystals,  and  the  interruption 
which  they  suffer  during  their  formation. 

The  faces  of  composition  are  those  in  which  two  or  more  individu- 
als touch  one  another.  They  are  rarely  smooth,  but  frequently 
streaked,  but  without  any  determined  direction.  In  rough  faces  of 
composition,  the  lustre  of  those  faces  is  very  low  ;  which  character 
may  be  used  to  distinguish  between  the  faces  of  cleavage  and  those 
of  composition.  And  they  maybe  distinguished,  from  uneven  faces 
of  fracture  by  comparing  them  with  real  faces  of  fracture  in  the  same 
individual. 

The  character  of  the  faces  of  composition  differ  from  those  of 
cleavage  and  crystalization  in  one  circumstance,  viz  :  they  do  not 
produce  regular  forms,  from  the  reason  that  they  preserve  no  deter- 
mined direction.  The  only  exception  which  it  is  necessary  to  make 
is  where  parallel  individuals  touch  one  another,  or  those  which  de- 
pend on  regular  composition. 


NOTES.  275 

NOTE  E. 

Polarised  Light. 

Light  reflected  from  polished  surfaces,  or  transmitted  through 
refracting  media,  with  a  certain  angle  of  incidence,  acquires  proper- 
ties entirely  different  from  those  which  it  before  possessed,  and  is 
called  polarised  light. 

For  example,  if  a  pencil  of  rays  fall  upon  a  plate  of  glass  at  an  an- 
gle of  incidence  of  56°  and  after  reflexion  be  received  with  the 
same  angle  of  incidence  upon  a  second  plate  so  placed  as  to  refleet 
them  in  a  plane  at  right  angles  to  that  in  which  they  first  moved,  al- 
most all  the  rays  refuse  to  be  reflected.  If  the  second  plate  be  now 
turned  around,  the  same  angle  of  incidence  being  maintained,  more 
and  more  rays  will  be  reflected,  until  the  plane  of  their  reflexion 
coincides  with  that  in  which  they  first  moved,  when  the  reflexion  is 
the  greatest  possible.  The  light  in  this  case  is  said  to  be  polarized; 
that  is,  the  rays  have  poles  or  sides  of  different  properties. 

From  the  various  phenomena  which  light  presents  when  decom- 
posed or  polarized  in  crystals,  mineralogists  are  enabled  to  judge  of 
the  mode  of  the  intimate  combination  of  the  particles  of  those  bodies : 
in  other  words,  they  give  an  insight  into  the  nature  of  their  crystaline 
structure.  The  light  which  passes  through  them  reveals  to  the  expe- 
rienced eye  the  peculiarities  in  the  mode  of  formation  and  composi- 
tion, acting,  as  it  were,  to  borrow  the  language  of  another,  as  a 
"  sounding  instrument,  with  which  to  probe  the  substance  of  matter, 
and  which,  insinuating  itself  between  the  minutest  parts,  permits  us 
to  study  their  arrangement,  at  which  previously  we  could  only  guess, 
by  inspecting  their  external  forms." 

Double  Refraction. 

Is  that  property  which  some  transparent  crystalized  bodies  possess 
which  enables  them  to  exhibit  a  double  image  of  an  object  seen 
through  them  in  certain  directions.  This  property  is  possessed  by  a 
great  number  of  minerals  and  artificial  salts.  In  all  doubly  refracting 
substances  there  are  one  or  more  lines,  or  one  or  more  planes  along 
'which  double  refraction  exists.  Those  substances  which  have  only 
One  line  or  plane,  are  called  crystals  with  one  axis,  or  one  plane 
of  axes  of  double  refraction.  And  those  which  have  two,*  three, 
four,  &c.,  axes,  or  planes  of  axes,  of  double  refraction.  Crystalized 
carbonate  of  lime,  or  as  it  is  commonly  called  Iceland  spar,  and  rhom- 
bohedral  quartz,  are  examples  in  which  this  property  resides.  Mine- 
rals which  belong  to  the  tessular  system  are  not  known  to  possess 
this  property. 


276  NOTES. 

NOTE  F, 

The  instrument  here  described  is  the  one  proposed  by  Benj.  H. 
Coates,  M.  D.,  in  the  Journal  of  Science,  p.  361—370,  vol.  1.  It 
consists  of  a  lever  like  a  common  steel-yard,  and  is  so  contrived  as  to 
balance  exactly  by  making  the  shorter  end  wider,  or  with  an  enlarg- 
ment  at  the  extremity.  The  upper  edge  is  rectilinear  and  free  from 
notches.  The  shorter  end  is  undivided,  but  on  the  longer  side  there 
is  a  scale,  of  which  every  division,  reckoning  from  the  extremity  of 
the  lever,  is  marked  with  a  number,  which  is  the  quotient  of  the 
length  of  the  whole  scale,  divided  by  the  distance  of  the  division  from 
the  end.  Thus  at  half  of  the  length  is  marked  the  number  2,  at  one- 
third  3,  at  one-fourth  4,  &c.  Also,  at  two-thirds  the  length  is  marked 
one  and  a  half,  at  two-fifths  two  and  a  half,  and  so  of  the  fractions 
sufficiently  minute.  These  numbers  extend  as  high  as  the  specific 
gravity  of  platina,  the  pivot  represents  unity,  and  a  notch  is  made  at 
the  farther  end. 

In  using  this  instrument,  any  convenient  weight  is  suspended  by  a 
hook  from  the  notch  at  the  end  of  the  scale.  The  body  under  ex- 
amination is  to  be  suspended  from  the  other  by  a  horse  hair,  and  slid 
along  till  an  equilibrium  is  produced.  It  is  then  without  alteration  to 
be  immersed  in  water  and  balanced  a  second  time,  by  sliding  the 
weight.  The  hook  of  the  latter  then  marks  the  specific  gravity  on  the 
scale.  By  this  instrument  it  will  be  seen  that  the  labor  and  incon- 
venience of  calculation  is  saved,  and  that  the  specific  gravity  of  any 
mineral  may  be  ascertained  in  a  few  moments,  without  pen  and  ink, 

NOTE  «. 

This  character  is  confined  mostly  to  iron  and  its  ores.  The  latter 
manifests  only  a  weak  degree  of  it,  but  is  generally  proportioned  to 
the  degree  of  oxidation.  ,  A  very  weak  magnetism  may  be  detected 
by  the  following  method  :  Place  a  magnet  on  a  level  with  a  needle, 
and  in  a  direct  line  with  it,  but  with  reversed  poles.  The  needle  will 
move  round  and  point  E  and  W,  which  shows  that  the  polar  attraction 
is  just  balanced,  being  divided  between  the  earth  and  the  magnet.  If 
now  a  mineral  with  only  a  small  quantity  of  iron  is  brought  near  the 
needle  it  will  act  upon  it;  whereas  in  the  ordinary  position  of  the 
needle  no  action  would  be  observed. 

NOTE  H. 

Chemical  Characters. 

The  facility  which  the  blow-pipe  affords  for  discovering  the  con- 
stituent parts  of  minerals,  especially  those  which  are  usually  termed 
metallic  compounds,  renders  it  necessary  to  say  something  on  the 
mode  of  using  that  instrument,  the  kinds  and  uses  of  the  fluxes  employ- 


NOTES.  277 

ed  for  reducing  the  metals  and  for  detecting  other  component  parts  of 
bodies,  &,c. 

For  general  use  the  common  blow-pipe  of  goldsmiths  will  answer 
all  the  purposes  of  a  more  expensive  kind,  and  as  experience  is  the 
only  way  to  become  master  of  it,  little  need  be  said  on  the  particular 
mode  of  using  it.  It  may  however  be  proper  to  say,  that  the  air 
should  not  be  forced  out  by  means  of  the  muscles  of  the  chest  but  by 
the  cheeks,  while  the  breathing  is  kept  up  through  the  nostrils,  and 
that  the  size  of  the  particle  of  the  mineral  operated  on  ought  in  gen- 
eral to  be  no  larger  than  a  common  pin  head. 

Of  the  combustible.  Every  kind  of  flame,  if  it  is  not  too  small, 
may  be  used  in  experiments  with  the  blow-pipe,  whether  it  be  that  of 
a  wax  or  tallow  candle,  or  of  an  oil  lamp,  the  latter  is  the  best.  The 
wick  ought  to  be  rather  large,  but  proportioned  to  the  tube  which  en- 
closes it.  The  best  fuel  is  said  to  be  olive  oil. 

Kinds  of  flame.  If  the  flame  is  examined  when  under  the  influence 
of  the  blow-pipe,  we  shall  remark  a  division  of  it  into  two  unequal 
parts  ;  the  external,  which  is  the  largest  and  most  luminous,  and  the 
internal  which  is  small,  well  defined,  and  of  a  blue  colour.  The  former 
is  called  the  oxidating  and  the  latter  the  reducing  flame.  The  great- 
est heat  is  just  at,  or  a  little  within,  the  apex  of  the  blue  flame,  and  is 
the  point  where  the  mineral  should  be  placed.  The  surrounding 
luminous  flame  tends  to  preserve  the  heat.  To  attain  the  greatest 
heat  we  must  not  blow  too  strongly  nor  too  gently  :  in  the  first  case, 
the  heat  is  carried  off  by  the  current  of  air,  and  in  the  second,  suffi- 
cient air  is  not  supplied  in  a  given  time. 

Effects  to  be  attained.  In  general  the  effects  we  wish  to  produce 
are  oxidation  and  reduction.  The  former  is  to  be  effected  by  expos- 
ing the  fragment  under  trial  before  the  extreme  point  of  the  flame, 
where  the  combustible  particles  are  soon  supplied,  or  saturated,  with 
oxygen.  Oxidation  goes  on  most  actively  at  an  incipient  red  heat, 
and  the  orifice  in  the  beak  of  the  blow-pipe  ought  to  be  larger  for  this 
kind  of  operation  than  in  reduction.  For  reduction  the  orifice  on  the 
beak  ought  to  be  rather  fine,  and  the  beak  should  not  be  inserted  too 
far  into  the  flame  of  the  lamp.  The  assay  must  be  exposed  to  the 
brilliant  part  of  the  flame  so  as  to  be  surrounded  by  it  on  all  sides,  and 
this  is  just  before  the  point  of  the  blue  flame  or  a  little  within  it. 

OF    THE    SUPPORT. 

1st.  Charcoal  That  charcoal  is  the  best  which  is  made  from  the 
pine  tree,  or  from  the  alder  or  the  light  woods  in  gener.il.  It  should 
be  well  burnt ;  that  which  splits,  crackles  and  smokes  is  unfit  for  use. 

2d.  Plalina.  In  using  platina  a  fine  wire  may  be  bent  into  the  form 
of  a  hook  at  the  extremity,  or  fused  into  a  globule  under  the  com* 

24 


278  NOTES. 

pound  blow-pipe,  and  then  flattened  and  shaped  into  the  form  of  a 
spoon,  or  we  may  use  platina  foil.  Each  form  has  its  advantages  un- 
der some  circumstances. 

3d.  A  fibre  of  Asbestus  is  sometimes  a  very  convenient  support. 

4th.  Plates  of  Mica  may  also  be  used. 

5th.  Glass  tubes  are  useful  as  well  as  necessary  to  roast  a  substance 
to  ascertain  what  it  is  combined  with.  One  or  two  inches  in  length 
and  the  1-8  of  an  inch  in  diameter  is  the  right  size,  and  open  at  both 
ends.  In  the  tube,  a  little  distance  from  one  end,  the  assay  must  be 
placed  :  it  may  be  heated  with  a  spirit  lamp  or  the  blow-pipe.  The 
volatile  substances  sublime  and  condense  in  the  upper  and  cooler 
part  of  the  tube. 

OF    THE    REAGENTS. 

The  reagents  employed  are  the  sub-carbonate  of  soda,  borate  of 
soda,  and  the  double  salt  formed  of  phosphate  of  soda  and  phosphate 
of  ammonia. 

1.  Soda.     Either  of  the  carbonates  may  be  used.     There  are  two 
principal  objects  to  be  obtained  by  their  use.     1st.  To  ascertain  the 
fusibility  or  infusibility  of  substances  which  are  combined  with  them, 
and  2d,  to  assist  in  the  reduction  of  the  metallic  oxides. 

(a)  The  fusion  of  bodies  by  Soda.     A  large  number  of  bodies  com- 
bine with  soda  at  high  temperatures,  but    many  are  infusible.     With 
silex,   the  acids,   arid  a  few  metallic  oxides,   it  forms  fusible   com- 
pounds.  The  quantity  of  soda  to  be  employed  may  be  taken  up  on  the 
point  of  a  knife,    previously  moistened,   and  then  intimately  mixed 
with  the  powder  of  the  assay.     This  must  be  dried  before  the  flame 
and  then  heated  till  it  fuses. 

(b)  Reduction  of  metallic  Oxides.   The  soda  in  the  reduction  of  me- 
tallic oxides  is  applied  in  powder  to  the  assay  as  long  as  any  matter 
of  the  assay  remains  on  the  charcoal.     The  place  where  the  assay  and 
soda  rested  on  the  charcoal  is  to  be  removed  with  a  knife  and  reduc- 
ed to  very  fine  powder  in  a  mortar.     This  powder  is  then  to  bs  wash- 
ed with  water  to  free  it  .from  charcoal.     If  the  assay  contained  no 
metallic  substance,  nothing  will  remain  after  the  last  washing.     But 
if  it  contained  any  portion  of  reducible  metal  it  will  be  found  at  the 
bottom  of  the  mortar,  either  in  the  form  of  brilliant  metallic  scales,  if 
malleable,  or  in  a  powder,  if  brittle  and  unmalleable.     In  either  case 
we  can  perceive  metallic  traces  on  the  bottom  of  the  mortar.    The 
metals  reducible  by  soda  are  gold,  silver,  tin,  molybdenum,  tungsten, 
antimony,  tellurium,  bismuth,  lead,  copper,  nickel,  cobalt  and  iron. 

2.  Borax  is  used  to  effect  the  solution  of  a  great  number  of  substan- 
ces.   In  using  this  reagent  we  are  to  notice  whether  a  solution  ia 
effected  ;  whether  effected  slowly  or  readily  ;  with,  or  without  effer- 
vescence. 


NOTES.  279 

Certain  bodies  have  the  property  of  forming  a  clear  glass  with  bo- 
rax, which  preserves  its  transparency  after  cooling,  but  when  slightly 
heated  by  the  exterior  flame  of  the  lamp,  becomes  opake  and  turns 
milk-white,  or  is  coloured,  particularly  if  the  flame  has  been  directed 
on  the  glass  in  an  unequal  and  intermitting  manner. 

Such  are  the  alkaline  earths,  yttria,  glucina,  zirconia,  the  oxides  of 
cerium,  columbium,  titanium.  The  same  thing  does  not  happen  with 
silica,  alumina,  the  oxides  of  iron  and  manganese,  or  when  silica  is 
present  in  a  compound. 

3.  Salt  of  Phosphorus.  This  salt  maybe  procured  by  dissolving  16 
partsof  sal  ammoniain  a  very  srnallquantity  of  boilingwater  and  adding 
100  parts  of  crystalized  phosphate  of  soda.  Liquify  the  whole  together 
by  heat,  and  filter  the  mixture  whilst  boiling  hot  ;  the  double  salt  will 
crystalize  in  grains  as  it  cools.  This  salt  is  particularly  applicable  to 
the  examination  of  metallic  oxides  whose  characteristic  colours  it  de- 
velopes, 

OTHER    REAGENTS. 

1.  Saltpetre  may  be  employed  to  discover  portions  of  manganese, 
too  minute  to  colour  glass  without  it. 

2.  Nitrate  of  Cobalt  is  used  to  detect  the  presence  of  alumina  and 
magnesia.    To  the  former  it  imparts  a  fine  blue,  and  to  the  latter  a 
pale  rose  colour.     To  be  employed  as  a  test   for  alumina  the  assay 
must  be  heated  strongly,  but  not  fused.     Jn  the  latter  case  the  assay 
must  be  fused. 

Tin.  This  metal  is  employed  in  the  state  of  foil,  cut  into  long 
strips  half  an  inch  wide,  and  closely  rolled  up.  Its  use  is  to  promote 
the  reduction  in  the  highest  degree  in  the  fused  vitreous  compounds, 
when  the  assay  contains  small  portions  of  the  metallic  oxides,  capa- 
ble of  being  reduced  to  protoxides.  We  are  to  introduce  into  the 
hot  assay,  previously  exposed  to  the  reducing  flame,  the  extremity  of 
the  roll  of  tin,  a  part  of  which  fuses  and  remains  in  the  assay,  and  the 
whole  is  immediately  remelted  in  the  same  flame. 

Iron.  This  is  used  in  the  form  of  fine  wire.  Bergmann  and  Gahn 
employed  it  to  precipitate  copper,  lead,  nickel  and  antimony,  and  to 
separate  them  from  sulphur  or  fixed  acids.  For  this  purpose,  a 
small  portion  of  one  end  of  the  wire  is  immersed  in  the  assay  when 
hot,  and  the  iron  becomes  covered  with  the  reduced  metal.  But  a 
more  important  use  of  iron  is  to  detect  phosphoric  acid.  Used  as 
above,  the  phosphates  are  reduced  to  the  state  of  phosphorus, 
which,  acting  on  the  iron,  produces  phosphuret  of  iron,  and  which, 
fusing  with  the  assay,  forms  a  white  brittle  metallic  globule. 

Certain  substances  undergo  a  change  of  form  and  aspect,  without, 
however,  entering  into  fusion.  Some  swell  up  like  borax,  or  form 
ramifications  which  have  a  cauliflower  appearance.  Others  afford  a 
btebby  glass.  In  the  use  of  fluxes  the  blast  ought  not  to  be  suspended 


280  NOTES. 

too  soon.  A  substance  may  at  first  seem  infusible,  but  after  a  few 
moments  begin  to  yield.  The  flux  ought  to  be  applied  in  small 
doses  at  a  time,  and  we  should  wait  till  the  first  has  united  with  the  as- 
say before  we  add  a  second  dose. 

When  operating  with  fluxes  before  the  reducing  flame,  it  sometimes 
happens  that  the  assay  globule  oxidates  as  the  charcoal  cools.  To 
obviate  this,  let  the  charcoal  be  turned  upside  down  while  the  globule 
is  still  fluid,  that  it  may  fall  on  a  metallic  plate.  In  conclusion  it 
way  be  remarked,  that  in  all  the  phenomena  which  the  assay  presents 
before  the  blow-pipe,  we  should  observe  the  action  of  both  flames, 
with  their  separate  effects,  all  of  which  ought  to  be  noted  down  sepa- 
rately. 

ACTION  OF  ACIDS. 

The  acids  usually  employed  as  chemical  tests  are  the  snlphuric, 
nitric  and  muriatic.  The  latter  is  the  best  to  discover  the  carbonates 
of  the  alkalies,  earths  and  metallic  oxides.  Either  of  them  may  be 
employed  for  this  purpose  in  a  diluted  state.  A  small  fragment  must 
be  detached  from  the  mass,  pulverized,  and  put  in  a  watch-glass  or 
wine-glass,  and  the  diluted  acid  poured  upon  it.  The  effervesence 
will  then  be  apparent,  from  the  liberation  of  the  carbonic  acid  gas- 

If  our  object  is  to  form  a  jelly  with  the  siiicated  earths,  a  large 
quantity  of  the  pulverized  mineral  must  be  employed,  and  the  acid 
used  undiluted.  It  is  commonly  necessary  to  employ  heat  for  digest- 
ing the  powder.  On  cooling  the  fluid  gelatinizes.  Occasionally  the 
colour  of  the  solution  is  to  be  noticed.  The  sulphuric  acid  is  used  un- 
diluted for  detecting  the  fluoric  acid.  The  powdered  mineral  in  this 
case  is  to  be  put  into  a  small  glass  tube,  and  the  acid  added,  and  then, 
heat  is  to  be  applied ;  when  if  any  fluoric  acid  is  present,  it  will  come 
off  and  corrode  the  glass,  or  diminish  its  transparency. 

NOTE  I. 

It  was  regarded  by  the  Abbe  Haiiy  as  an  axiom  in  crystalography^ 
that  two  minerals  may  possess  analogous  forms,  each  for  instance 
a  rhombic  prism,  yet  the  dimensions  of  those  prisms  are  different. 
Identity  of  form,  therefore,  (not  including  the  tessular  system)  was 
thought  to  indicate  identity  of  composition.  In  the  year  1819,  a  dis- 
covery was  made  by  Prof.  Mistcherlich,  of  Berlin,  relative  to  the  con- 
nexion between  crystaline  form  and  chemical  composition,  which  is 
exceedingly  important  to  mineralogy  and  chemistry.  It  appears 
from  his  investigations,  that  certain  substances  are  capable  of  being 
substituted  for  each  other  in  combination,  without  influencing  the  form 
of  the  compound.  This  remarkable  fact  has  been  ably  traced  by  Prof. 
Mistcherlich,  in  the  salts  of  phosphoric  and  arsenic  acid.  Thus  the 
neutral  phosphate  and  bi-phosphate  of  soda  have  exactly  the  same 


:    f  NOTES.  281 

form  as  the  arseniate  and  bi-arseniate  of  soda.  The  same  has  been 
shown  of  other  salts  and  minerals.  From  these  and  analogous  facts, 
it  appears  that  certain  substances,  when  similarly  combined  with  the 
same  body,  are  disposed  to  affect  the  same  crystaline  form.  This 
discovery  has  led  to  the  formation  of  groups,  each  comprehending 
substances  which  crystalize  in  the  same  forms,  and  which  are  hence 
termed  iso-morphous. 

Another  fact  connected  with  the  preceding  remarks  is,  that  some 
substances  may  assume  two  fundamental  forms.  For  instance,  car- 
bonate of  lime  yields  a  rhomboid,  and  a  right  rhombic  prism.  Other 
instances  of  the  kind  may  yet  be  discovered,  which  will  serve  to  con- 
firm the  fact  or  disprove  it. 

NOTE   K. 

The  process  by  which  a  mineral  is  determined  is  as  follows  :  first  its  form, 
whether  it  be  regular  or  irregular  ;  if  it  is  regular,  what  is  the  Primary  form — 
then  the  hardness  and  specific  gravity  must  be  determined  with  proper  accura- 
cy. The  specific  character  requires  these  data  ;  they  are  of  use  also  in  the 
classes,  orders  and  genera.  After  this  examination  the  characteristic  may  be 
applied,  and  it  will  at  the  same  time  point  out  what  other  characters  are  want- 
ing. The  given  individual  is  now  to  be  carried  through  the  subordinate  char- 
acters of  the  classes,  orders,  genera  and  species,  one  after  the  other,  comparing 
its  properties  with  the  characteristic  marks  contained  in  the  characters  of  the 
systematic  unities.  From  their  agreement  with  some,  and  their  difference 
from  other  characters,  we  infer  that  the  mineral  belongs  to  one  of  the  classes, 
to  one  of  the  orders,  to  one  of  the  genera,  and  to  one  of  the  species.  Having 
in  this  manner  advanced  to  the  character  of  the  species,  it  will  generally  be 
necessary  to  ascertain  the  dimensions  of  the  form.  The  common  goniometer 
will  in  most  cases  answer  our  purpose.  It  is  seldom  necessary  to  read  over 
the  whole  of  any  character  of  a  class,  order  or  genus  ;  one  term  that  does  not 
agree  suffices  for  its  exclusion.  To  illustrate  this  process  more  particularly, 
let  us  take  an  example  :  first  let  the  mineral  yield  by  mechanical  division  a 
cube,  let  its  hardness=2.5  and  its  sp.  gr.  7.4—7.6.  In  this  case  the  specific 
gravity  excludes  it  from  classes  first  and  third  :  hence  it  belongs  to  class  sec- 
ond. Comparing  now  the  properties  of  the  individual  with  the  characters  of 
the  orders  in  the  second  class,  we  shall  find  that  its  specific  gravity  is  too  great 
for  the  orders  Haloide,  Baryte,  Malachite,  Mica,  Spar,  Gem  and  Sulphur,  and 
is  excluded  from  Pyrites  by  its  less  degree  of  hardness.  The  consideration  of 
other  characters  now  requires  attention,  as  both  hardness  and  specific  gravity 
fall  within  the  limits  of  orders  Kerate,  Metal,  Glance  and  Blende.  If  the  min- 
eral has  a  metallic  lustre  it  is  excluded  from  the  order  Kerate.  Our  mineral 
then  belongs  to  one  of  three  orders,  Metal,  Glance  or  Blende.  In  the  order 
Metal  the  lustre  is  metallic,  colour  not  black,  which  is  indecisive,  and  both 
hardness  and  specific  gravity  bring  it  within  the  limits  of  the  order  Metal,  but 
if  the  colour  is  gray  the  mineral  must  be  malleable,  which  excludes  the  miner- 
al under  examination  from  this  order,  as  ours  is  not  malleable,  and  this  exclu- 
sion leads  us  next  to  consider  the  order  Glance.  First,  our  mineral  is  metallic 
and  colour  is  gray,  and  both  hardness  and  specific  gravity  include  the  mineral 

24* 


NOTES. 

under  examination.  If  the  cleavage  is  monotomous  the  gravity  will  be  under 
5.0,  but  the  gravity  being  above  5.0  the  cleavage  is  of  no  consequence — the 
gravity  in  the  order  Glance,  together  with  the  other  characters,  agreeing  with 
the  one  under  examination,  we  infer  that  it  belongs  to  the  order  Glance.  In 
comparing  our  mineral  with  the  genera  in  the  order  Glance,  we  shall  find  that 
it  will  be  excluded  from  the  genus  Copper-glance,  both  by  the  character  of 
cleavage  and  greater  specific  gravity,  and  from  Silver-glance  by  its  greater 
specific  gravity  and  a  want  of  malleability,  and  that  it  agrees  with  Lead-glance 
in  colour,  hardness,  specific  gravity  and  cleavage ;  hence  we  infer  that  our 
mineral  belongs  to  the  genus  Lead-glance,  and  as  this  genus  comprehends  but 
one  species,  it  renders  it  probable  that  our  mineral  is  Hexahedral  Lead-Glance, 

CHARACTERS  OP  THE  CLASSES  AND  ORDERS. 

Characters  of  the  Classes. 

CLASS  I. 
Gravity  under  3.8 

No  bituminous  odor. 
Solid:  taste. 

i         CLASS  II. 

Gravity  above  1.8 
Tasteless. 

CLASS  III. 
Gravity  under  1.8 

Fluid:  bituminous  odor. 
Solid:  no  taste. 

Cliaracters  of  the  Orders. 
Characters  of  the  Orders  of  Class  I. 

I.  ORDER — GAS. 

G.=0.0001— 0.0014 

Expansible. 

Not  acid. 

II.  ORDER WATER. 

G.=1.0 

Liquid. 

Without  odor  or  taste. 

III.  ORDER ACID. 

G.=0.0015— 3.7 

Acid. 

IV.  ORDER — SALT. 
G.=1.2— 2.9 

Solid. 
Not  acid. 


NOTES.  283 

Characters  of  the  Orders  of  Class  II. 

I.  ORDER HALO1DE. 

Non-metallic. 

Streak  uncoloured. 

H.=1.5— 5.0 

G.=2.2— 3.3 

Pyramidal  or  prismatic:  H. =4.0,  and  less,  cleavage  imper- 
fect, in  oblique  directions. 
Cleavage  regular  octahedron:  'H.=4.0. 
Cleavage  monotomous,  eminent:  G.=2,4,and  less. 
H.  under  2.5:  G.=2.4,  and  less. 
G.=2.4,  and  less :  H.  under  2.5,  no  resinous  lustre. 

II.  ORDER BARYTE. 

Non-metallic. 

Streak  uncoloured,  or  orange  yellow. 
H.=2.5— 5.0 
G.=3.3— 7.3 

Cleavage  monotomous  :  G.=4»0,  and  less ;  or=5,  and  more. 
Lustre  adamantine  or  imperfect  metallic :  G.=5.0,and  more. 
Streak  orange-yellow  :  G.=6.0,  and  more. 
H.=5.0:  G.  under  4.5. 
G.  under  4.0,  and  H.=5.0:  cleavage  prismatic. 

III.  ORDER — KERATEt 

Non-metallic. 
Streak  uncoloured. 

Cleavage  not  monotomous,  not  perfect  perHomous. 
H.=1.0.— 2.0 
G.  above  5.5 

IV.  ORDER — -MALACHITE. 

Non-metallic. 

Colour  blue,  green,  brown. 
Cleavage  not  monotomous. 
H.=1.0— 5.0 
G.=2.0— 4.6 

Colour  or  streak  brown  :  H.=3.0,  and  less ;  G.  above  2.5. 
Streak  blue  :  H.=4.0,  and  less. 
Streak  unclouded :  G.=2.2,  and  less ;  H.  under  3.0. 

V.  ORDER MICA. 

Cleavage  monotomous,  eminent. 
H.=l. 0—4.5 
G.=1.8— 3.2 
Metallic:  G. under 2.2. 
Non-metallic :  G.  above  2.2. 


284  NOTES. 

H.=3.0,  and  more  :  rhombohedral. 
G.  under  2.5  :  metallic. 

VI.  ORDER SPAR. 

$Lnr.  Non-metallic. 

Streak  uncoloured... brown,  blue. 
H.=3.5— 7.0 
G.=2.0— 3.7 

Forms  cube,  tetrahedron,  regular  octahedron,  rhombic  dode- 
cahedron :  G.=3.0,  and  less. 
Rhombohedral :  G.=2.2,  and  less ;  or  H.==6.0. 
H.=4.0,  and  less  :  cleavage  rnonotomous,  eminent. 
H.  above  6.0 :  pearly  lustre  ;  G.  under  2.5,  or  above  2.8. 
G.  above  3.3 :  forms  right  rhombic  and   oblique  rhombic 
prisms,  or  doubly  oblique  prisms  ;  or  H.=6.0  ;  no  ada- 
mantine lustre. 
G.=2.4,  and  less  :  not  without  traces  of  forms  and  cleavage. 

VII.  ORDER GEM. 

Non-metallic. 

No  metallic  adamantine  lustre. 
Streak  uncoloured. 
H.=5.5— 10.0 
G.=1.9— 4.7 
H.=6.0,  and  less:  tessular,  G.=3.1,  and  more  ;  or  G.=2.4, 

and  less,  and  no  traces  of  form  and  cleavage. 
G.  under  3.8:  no  pearly  lustre  upon  faces  of  cleavage. 

VIII.  ORDER ORE. 

No  green  streak. 

H. =2. 5— 7.0 
G.=3.4— 7.4 
Metallic :  colour  black. 

Non-metallic :  lustre  adamantine,  or  imperfect  metallic. 
Streak  yellow  or  red  :  H.=3.5,  and  more,  G.=4.8,  and  more. 
Streak  brown  or  black:  H.=5.0,  and  more;  or  cleavage 

monotomous. 

H.=4.5,  and  less  :  streak  yellow,  red  or  black. 
H.=6.5,  and  more,  and   streak  uncoloured:  G.=6.5,  arid 
more. 

IX.  ORDER — METAL. 

Metallic. 

Colour  not  black. 

H.=0.0— 5.0 

G. =5.7— 20.0 

Colour  gray:  malleable,  G.=7.4,  and  more. 
H.  above  4.0  :  malleable. 


NOTES.  285 

X.  ORDER PYRITES. 

Metallic. 

H.=3.0— 6.5 

G.=4.1— 7.7 

H.=4.5,  and  less  :  G.  under  5.3 
G.=5.3,  and  less ;  colour  yellow  or  red. 

XI.  ORDER GLANCE. 

Metallic.   . 
Colour  gray -black. 
H.=l.  0—4.0 
G.=4.2— 7.6 

Cleavage  monotomous;  G.  being  under  5.0:  colour  lead- 
gray. 
G.=above  7.4 :  colour  lead-gray. 

XII.  ORDER — BLENDE. 

Streak  green,  red,  brown,  uncoloured. 

H.=1.0— 4.0 

G.=3.9— 8.2 
Metallic :  colour  black. 
Non-metallic:  lustre  adamantine. 
Streak  green :  colour  black. 
Streak  brown.. .uncoloured:  G.  between  4.0  and  4.2,  form 

tessular. 

Streak  red :  H.=2.5,  and  less. 
G.^4.3,  and  more  :  streaC  red. 

XIII.  ORDER SULPHUR. 

Non-metallic. 
Colour  yellow,  red,  brown. 

Prismatic. 
H.=l. 0—2.5 
G.=1.9— 3.6 

Cleavage  monotomous  :  G.=3.4,  and  more. 
G.  above  2.1 :  streak  yellow  or  red. 

Characters  of  the  Orders  of  Class  III. 

I.  ORDER RESIN. 

H.=0.0— 2.5 
G.=0.7— 1.6 
G.=1.2,  and  more :  streak  uncoloured. 

II.  ORDER COAL. 

Streak  brown,  black. 

H.=l.  0—2.5 
G.=1.2— 1.5 


286  NOTES. 

NOTE  L. 

NON-METALLIC  COLOURS. 
A.      WHITE. 

1.  Snow-white.    The  colour  of  newly  fallen  snow.    Ex.  Rhombohe- 

dral  lime-haloide,  or  the  purest  white  marble. 

2.  Reddish-white.     White  somewhat  inclining  to  red.    Ex.   Several 

varieties  of  rhombohedral  lime-haloide. 

3.  Yellowish-while.     White  inclining  to  yellow.     Ex.  Several  var. 

of  uncleavable  quartz. 

4.  Grayish-while,.    White  inclining  to  gray.    Ex.  Common  limestone. 

5.  Greenish-white.     White  inclining  to  green.     Ex.  Common  talc. 

6.  Milk-white.    White  inclining  to  blue*     Ex.  Chalcedony. 

B.  GRAY. 

1.  Bluish-gray.    Gray  inclining  to  blue,  rather  dirty.     Ex.  Splintery 

hornstone. 

2.  Pearl-gray.     Gray  mixed  with  red  and  blue.     Ex.  It  is  pale  in  the 

pearls,  but  of  the  same  kind. 

3.  Smoke-gray.   Gray  mixed  with  brown.    The  colour  of  thick  smoke. 

4.  Greenish-gray*    Gray  mixed  with  green.  '  Ex.  Several  varieties  of 

rbombohedral  quartz,  or  cats-eye,  &c. 

5.  Yellowish-gray.     Gray  mixed  with  yellow.    Ex.  Flint. 

6.  Ash-gray.     A  mixture  of  black  and  white.    Ex.  Zoisite. 

C.  BLACK. 

1.  Grayish-black.    Black  mixed  with  gray.    Ex.  Basalt. 

2.  Velvet-black.    Colour  of  black  velvet. 

3.  Greenish-black.    Black  mixed  with  green.    Ex.  Some  varieties  of 

augite-spar. 

4.  Brownish-black.     Black  mixed  with  brown.     Ex.  Bituminous  mine- 

ral coal. 

5.  Bluish-black.    Black  mixed  with  blue.    Ex.  Black  cobalt,  the  reni- 

form  and  botryoidal  varieties  from  Thuriugia. 
D.     BLUE. 

1.  Blackish-blue.    Blue   mixed  with  black.      Ex.  Prismatic  azure- 

malachite. 

2.  Azure-blue.    A  very  bright  blue  mixed  with  red.   Ex.  Lapis  Lazuli. 

3.  Violet-blue.    Blue  mixed  with  red.    Ex.  Amethyst. 

4.  Lavender -blue.    Blue  with  a  little  red  and  much  gray.    Ex.  Litho- 

marge. 

6.  Plum-blue.    A  colour  somewhat  inclining  to  brown,  and  like  som« 

varieties  of  plums.    Ex.  Dodecahedral  corundum. 
6.  Prussian  or  Berlin-blue.    The  purest  blue  colour.    Ex.  Prismatic 
disthene-spar. 


NOTES.  287 

7.  Smalt-blue.  Ex.  The  colour  of  some  varieties  prismatoidal  gypsum- 

haloide. 

8.  Indigo-blue.    Blue  mixed  with  black  and  green.    Ex.  Prismatic 

iron-mica. 

9.  Duck-blue.    Blue  with  a  great  deal  of  green  and  a  little  black. 

Ex.  Ceylanite. 

10.  Sky-blue.    A  pale-blue  colour,  with  a  little  green. 

E.     GREEN. 

1.  Verdigris-green.    A  green,  inclining  tb  blue.     Colour  of  verdigris. 

2.  Celandine-green.    Green  mixed  with  blue  and  gray.     Ex.    Pris- 

matic talc-mica. 

S.  Mountain- green.      Green  with  a  great  proportion  of  blue.     Ex. 
Rhombohedral  emerald. 

4.  Leek-green.  Green  with  a  little  brown.  Col.  of  the  leaves  of  garlic. 

5.  Emerald-green.    The  purest  green  colour.     Ex.  Emerald. 

6.  Apple-green.    A  light-green  colour,  with  a  trace  of  yellow.    Ex. 

Chrysophrase. 

7.  Grass-green.    The  colour  of  fresh  grass. 

8.  Pislachio-green.      Green  with  yellow  and  a  little  brown.      Ex. 

Prismatic  chrysolite. 

9.  Asparagus- green.    Pale-green,  with  a  great  proportion  of  yellow. 

Ex.  Asparagus  stone. 

10.  Blackish-green.     Green  with  black.    Ex.  Paratomousaugite-spar, 

11.  Olive-green.     Pale-green,  with  a  great  deal  of  brown  and  yellow, 

Ex.  Some  varieties  of  olivine. 

12.  Oil-green.     A  green  still  lighter,  or  more  yellow  and  less  brown. 

The  colour  of  olive-oil. 

13.  Siskin-green.     A  light-green  colour,  very  much  inclining  to  yel- 

low.    Ex.  Pyramidal  euchlose-mica. 

F.    YELLOW. 

1.  Sulphur-yellow.    Colour  of  pure  sulphur. 

2.  Straw-yellow.    A  light-yellow  with  a  little  gray.     Ex.  Prismatic 

topaz. 

3.  Wax-yellow.    Yellow  with  gray  and  a  little  brown. 

4.  Honey-yellow.    Yellow  with  a  little  red  and  brown.     The  dark 

colour  of  honey. 

6.    Lemon-yellow.     The  purest  yellow   colour.      Ex.    Prismatoidai 
sulphur. 

6.  Ochre-yelhw.    Yellow  with  brown.    Ex.  Those  varieties  of  quart* 

which  are  much  mixed  with  iron. 

7.  Wine-yellow.     A  pale-yellow  colour,  with  a  little  red  and  gray. 

Ex.  Prismatic  topaz. 

8.  Cream- yellow.    A  pale-ye'!ovr,  with  a  little  red  and  very  little 

brown.     Some  varieties  of  lithomarge. 


288  NOTES. 

9.  Orange-yellow.    Yellow,  very  much  inclining  to  red.    The  colour 
of  ripe  oranges. 

G.    RED. 

1.  Aurora-red.    Red  with  much  yellow.    Ex.  Hemiprismatic  sulphur. 

2.  Hyacinth-red.    Red  with  yellow  and  a  little  brown.     Ex.  Pyra- 

midal zircon. 

3.  Brick-red.    Red  with  yellow,  brown  and  gray,  i   Colour  of  newly 

baked  bricks. 

4.  Scarlet-red.    The  brightest  red  colour,  with  a  slight  tint  of  yellow. 

Ex.  Cinnabar. 

5.  Blood-red.    Red  with  a  little  of  yellow  and  black;  the  colour  of 

blood.    Ex.  Dodecahedral  garnet. 

6.  Flesh-red.     A  pale-red  with  gray  and  a  little  yellow.    Ex.  Pris- 

matic hal-baryte. 

7.  Carmine-red.    The  purest  red  colour.    Rare.     Some  varieties  of 

copper-ore. 

8.  Cochineal-red.    Red  with  a  little  blue  and  gray. 

9.  Rose-red.     A  pale-red  mixed  with  white  and  a  little  gray.    Ex. 

Rhombohedral  quartz. 

10.  Crimson-red.    Red  with  a  little  blue.    Ex.  Prismatic  cobalt-mica. 

11.  Peachblossom-red.     Red  with  white,  and  more  of  gray  than  rose- 

red.    The  colour  of  peach  blossom. 

12.  Columbine-red.    Red  with  a  little  blue  and  much  black.    Distinct 

in  dodecahedral  garnet. 

13.  Cherry-red.    A  dark  red  colour  mixed  with  much  blue  and  a  little 

brown  and  black.    Ex.  Prismatic  purple-blende. 

14.  Brownish-red.    Red  with  much  brown.    Ex.  Reddle. 

H.     BROWN. 

1.  Reddish  brown.    Brown  mixed  with   much  red.    Ex.  Pyramidal 

zircon. 

2.  Clove-brown.    Brown  with  red,  a  little  blue.    Ex.  Axinite. 

3.  Hair-brown.    Brown  with  a  little  yellow  and  gray.    Ex.  Prismatic 

iron-ore. 

4.  Broccoli-brown.    A  brown  colour  mixed  with  blue,  red  and  gray. 

Rare.     Ex.  Pyramidal  zircon. 

5.  Chesnut-brown.    The  purest  brown  colour.      Ex.    Quartz  mixed 

with  the  brown  oxide  of  iron. 

6.  Yellowish-brown.    Brown  with  much  yellow.    Ex.  Jasper. 

7.  Pinchbeck-brown.     Yellowish -brown  with  a  metallic  lustre.     Ex. 

Rhombohedral  talc-mica. 

8.  Wood-brown.    Brown  with  yellow  and  gray.     The  colour  of  rotten 

wood. 

9.  Liver-brown.    Brown  with  gray  and  a  little  green.    Ex.  Common 

jasper. 

10.  Blackish-brown.     Brown  with  much  black.    Ex.   The  mineral 


INDEX. 


Mrasite,  168  ^ 
Acicular  olivinite,  85 
Acid,  39 

arsenious,  41 

"boracic,  41 

carbonic,  39 

muriatic,  40 

sulphuric,  40 
Acmile,  129 
Mynolite,  126 
Adhesive  slate,  253 
Adularia,  119 
Aeriform  carbonic  acid,  39 
Aeschinite,  229 
Agalmatolite,  237 
Agaric  mineral,  61 
^/6tn,  113 
Albite,  120 
Allagite,  137 
Allanite,  184 
Allochroile,  180 
Allophane,  229 
wftwm,  47 
Jttum-haloide,  56 

stone,  56 

slate,  253 

salt,  47 

Alumine,  sub-phosphate  of,  64 
Amalgam,  190 

native,  190 
Amazon  stone,  119 
.tfm&er,  225 
Jlmblygonite,  131 
Amethyst,  150 
Ammonia,  muriate  of,  46 
sulphate  of,  46 
Ammoniac  salt,  46 
Analcime,  109 
Anatase,  170 
Andalusite,  140 
Anhydrite,  54 
Anhydrous  sulph.  lime,  54 
Anorthite,  122 
Anihophyllite,  103 

hydrous,  103 
Anthracite,  228 
Antimony-glance,  211 
Antimonial  silver,  189 


Antimony,  188 

dodecahedral,  188 
gray,  211,  212 
native,  188 

nickeliferous  gray,  204 
rhombohedral,  188 
octahedral,  189 
oxide  of,  81 
prismatic,  189 
prismatic  white,  81 
red,  220 
sulphuret  of,  211 
Antimony-baryte,  81 
Antimony-blende,  220 
Antimony-glance,  211,  230 

axotomous,  212 
prismatoidal,  212 
Apatite,  57 
Aphrite,  62 
Aplome,  161 
Apophyllite,  113,  114 
Arfvedsonite,  13(J 
Argentine,  62 

Argentiferous  copper-glance,  213 
Arragonite,  59 
Arseniate  of  cobalt,  93 
of  copper,  84 

octahedral,  84 
right  prismatic,  85 
rhomboidal,  91 
of  iron,  84 
of  lead,   75 
of  lime,  66 
Arsenic,  187 
Arsenic-glance,  230 
oxide  of,  40 
native,  187 

Arseniet  of  antimony,  229 
Arsenical  bismuth,  230 
iron,  197 
nickel,  195 
pyrites,  196 
axotomous,  196 
di-prismatic,  197 
prismatic,  196 
Asbestus,  124 
Atacamite,  88 
Atmospheric  air,  38 
25 


290 


INDEX. 


Augile,  123 

spar,  123 

hemi-prismatic,  124 
paratomous,  123 
prismatic,   127 
prismatoidal,   126 
straight-edged,  124 
oblique-edged,  123 
Jiutomalite,  142 
Jlventurine  feldspar,  119 
Axij "Tangible  gypsum,  52 
baryte,  73 

kouphone-zeolite,  113 
Axinite,  153 

prismatic,  153 

Jlxotomous  antimony-glance,  212 
lead-baryte,  78 
arsenical  pyrites,  196 
iron-ore,  177,241 
kouphone-spar,  114 
triphane-spar,  105 
augite-spar,  230 
Azure-malachite,  86 

prismatic,  86 
Azure-spar,  128 

dodecahedral,  128 
prismatic,  128 
prismatoidal,  129 
Azure  stone,  128 
dzurite,  128 

Babingtonile,  130 
Baikalite,  124 
Baryte,  67 

axifrangible,  73 

•  carbonate  of,  71 

prismatic,  72 
di-prismatic,  71 
prismatoidal,  73 
rhomboidal,  71 
Baryto-calcite,  73 
Barytes,  sulphate  of,  72 
Bergmanite,  131 
Berthierite,  230 
Beryl,  147 
Beudantite,  230 
Bi-borate  of  soda,  45 
Bi-seleniuret  of  zinc,  230 
Si-silicate  of  zinc,  137 

manganese,  137 
magnesia,  232 
nismuth,  189 

arsenical,  230 
cupreous,  215 
native,  189 
octahedral,  189 


Bismuth,  sulphuret  of,  210 
Bismuth-glance,  210 

prismatic,  210 
prismatoidal,  247 
Bismuth-blende,  230 

cobalt-ore,  231 
Bismuthic  silver,  214 
Bitter-spar,  62 
Bitumen,  225 
Bituminous  limestone,  61 

mineral-coal,  227 
shale,  254 
Black  coal,  227 
chalk,  254 
iron-ore,  182 
lead,  95 
cobalt-ochre,  231 

ore,  231 

mineral-resin,  225 
hematite,  182 
tellurium,  209,  219 
wad,  183 

yttro-tantalite,  186 
Blende,  218 
Blind  coa\,  228 
Bloedite,  49 
Blue  copper,  86 

carbonate  of,  86 
Blue  feldspar,  129 
lead,  207 
spar,  129 
vitriol,  51 
Bole,  254 
Boltonite,  232 
Boracic  acid,  41 
Boracile,  155 
Borat&oi  lime,  107 

magnesia,  155 
soda,  45 
Borax,  45 
Borax-salt,  45 
Botrjjogene,  232 
Botryolite,  106 
Bournonite,  206 
Brachytypous  lime-haloide,  63 
manganese-ore,  232 
parachrose-baryte,  67 
Braunite,  232 
Breislakite,  232 
Brewsterite,   114 
Brythene-salt,  48 
Bright  white  cobalt,  197,  199 
Brittle  sulphuret  of  silver,  212 
Brochantite,  89 
j&ro»  silk,  101 
Brookite,  184' 


INDEX. 


291 


Brown  coal,  227 
lead-spar, 
Brucite,  164 
Bucholzite,  140 
Bucklandite,  132 
Bustamite,  232 

Cacholong,  151 

Calamine,  69 

electric,  68 
prismatic,  68 
rhombohedral,  69 

Calaite,  132 

Calcareous-spar,  60 

heavy-spar,  232 
tufa,  61 

Calcedony,  150 

Canntl  coal,  227 

Carbonate  of  barytes,  71 
bismuth,  232 
copper-green,  88 
blue,  86 
lead,  14 
iron,  67 
lime,  60 
magnesia,  65 
magnesia  &,  iron,  63 
manganese^  68 
soda,  42 
strontian,  70 
zinc,  69 

Carbonic  acid,  39 

Carburett&d  hydrogen,  37 

Cornelian,  150 

Cats-eye,  150 

Celesl'ine,  73 

Cellular  pyrites,  201 

Ceriwe,  176 

Cerium-ore,  175 

uncleavable,  175 

Chabasie,   110 

Cliabasite,  110 

Chalk,  61 

Chalkosiderite,  232 

Chamoisite,  233 

Cliiaslolite,  132 

ChUdrenite,  66 

Chlorite,  95 

Chloropal,  233 

Chlorophaeite,  233 

Chlorophane,  57 

Chondrodite,  164 

Clirtsite,  233 

Chromaie  of  iron,  176 
lead,  76 
lead  and  copper,  96 


Chrome-ore,  176 
Chrysoberyl,  144 
Chrysocolla,  83 
Chrysoprase,  150 
Cinnabar,  222 

hepatic,  222 
bituminous,  222 
Cinnamon-stone,  161 
C%,  254 

common,  254 
Cleavelandite,  121 
Coa/,  227 

slate,  227 
foliated,  227 
coarse,  227 
cannel,  227 
pitch,  227 
earthy,  227 
Cofiaft  arseniate  of,  93 
arsenical,  197 
bright  white,  197 
prismatic  red,  93 
sulphate  of,  52 
Cobalt-kies,  203 
Cobalt-mica,  93 
Cobalt-ore,  gray,  198 
Cobalt-pyrites,  197 

hexahedral,  197 
Cobaltic  galena,  214 

lead-glance,  214 
Coccolite,  123 
Cockscomb-pyrites,  201 
Colophonite.  159 
Columbite,  174 
Common  copper-green,  83 
clay,  254 
quartz,  150 
salt,  44 

schiller-spar,  100 
Comptonite^  115 
Condrodite,   164 
Condurrite,  233 
Copper-black,  203 
Co^er,  194 

blue  carb.  of,  86 
green  carb.  88 
hydrous  phosphate  of,  87 
martial  arseniate  of,  90 
muriate  of,  88 
native,  194 
Copper-ore,  171 

arseniate  of,  91 
octahedral,  171 
phosphate  of,  85 
prismatic  arseniate  of,  85 
red-oxide  of,  171 


292 


INDEX. 


Copper,  rhomboidal  arseniate 

of,  91 

seleniuret  of,  217 
sulphate  of,  51 
sulphuret  of,  206 
triple  sulphuret  of,  206 
velvet-blue,  91 
vitreous,  206 
Copper-glance,  205 

argentiferous,  213 
di-prismatic,  206 
prismatic,  206 
prismatoidal,  205 
rhomboidal,  206 
tetrahedral,  205 
Copper-green,  83 

uncleavable,  83 
black,  203 
gray,  205 
Copper-mica,  91 
Copper-nickel,  195 
Copper-ore,  171 

octahedral,  171 
foliated,  172 
capillary,  172  • 
compact,  172 
Copper-pyrites,  202 

octahedral,  202 
pyramidal,  202 
purple,  202 
yellow,  202 
variegated,  202 
Corneous  lead,  79 

manganese,  137 
mercury,  83 
silver,  82 
Corundum,  141 

dodecahedral,  141 
r  -*  octahedral,  142 
prismatic,  144 
rhombohedral,  ,142 
rhomboidal,  142 
Cotturnile,  234 
Couzeranite,  234 
Crichtonite, 
Cronstedite,  99 
Crosstone,  109 
Cryolite,  55 
Cryone-haloidc,  55 
,  Crysoberyl,  144 
Cube-ore,  84 
Cummingtonite,  234 
Cupreous  bismuth,  215 
analcime,  234 
manganese,  234 
sulphate  of  lead,  79 


Cupreous   sulphate-carbonate    of 

lead,  79 
Cupriferous  sulphuret  of  bismuth, 

215 

Cyanite,  104 
Cyprine,  158 

Dark-red  silver,  222 
Davite,  48 
Derrnatine,  235 
Deweylite,  235 

Diatomous  antimony-phyllite,  234 
kouphone-spar,  110 
schiller-spar,  100 
Diamond,  145 

octahedral,  145 
common,  145 
Diallage,  (in  part,)  100 
Diopside,  124 
Dioptase,  87 
Disthenc-spar,  104 

prismatic,  104 
Distome-spar,  106 

prismatic,  106 
Di-pristnatic  hal-baryte,  71 
lead-spar,  74 
olivenite,  84 
olive  malachite,  85 
zeolite,  110 

Dodecahedral  antimony,  188 
azure-spar,  128 
corundum,  141 
iron-ore,  178 
garnet,  158 

farnet-blende,  219 
ouphone-spar,  10S 
mercury,  190 
zeolite,  107 
zinc-blende,  219 
Dolomite,  62 
Drawing  slate,  254 
Dysluite,  235 
Dysodile,  235 

Edingtonite,  235 
Emerald,  147 

oriental,  143 

prismatic,  147 

copper,  87 

malachite,  87 

rhombohedral,  87 
Emery,  143 

Empyreumatic  hydrogen  gas,  37 ' 
Empyrodox  quartz,  152 
Epidote,  126 
Erlanite,  236 


INDEX. 


293 


Essonite,  161 
Eucairite,  215 
Euclase,  147 
Euchroite,  89 
Euchlore  mica,  91 
Eudialite,  133 

Fahlers,  205 
Fahlunite,  236 
Fassaite,  124 
Feldspar,  118 

rhomboidal,  118 
rhombohedral,  118 
prismatic,  118 
aventurine,  119 
fetid,  119 
labrador,  119 
blue,  129 
pyramidal,  121 
prismato-pyramidal  12 
Ferruginous  platina,  236 

silicate  of  manganese,  13 
Ferro-silicate  of  mangenese,  138 
Fergusonite,  184 
Fibrolile,  237 
Figurestone,  237 
Flinty  slate,  150 
Fluate  of  lime,  56 
Fluellite,  66 
F/wor,  56 

haloide,  57 
octahedral,  56 
rhombohedral,  57 
Fosterite,  165 
Fowlerite,  138 
Franklinite,  178 
Frugardite,  158 
Fuller's  earth,  255 

Gadolinile,  164 

prismatic,  164 
galena,  208 
hexahedral,  208 
antimoniated,  208 
argentiferous,  208 
Garnet,  157,  158 
Garnet-blende,  219 

dodecahedral,.  219 
Garnet,  pyramidal,  157 

dodecahedral,  158 
common,  159 
precious,  159 
tetrahedral,  158 
manganesian,  160 
prismatoidal,  162 
prismatic,  162 

25 


Gas,  37 

marsh,  37 
Gaylussite,  50 
Gem,  140 
Gibbsite,  237 
Gismondine,  168 
Gieseckite,  237 
Glauber-salt,  42 

prismatic,  42 
Glauberite,  48 
Glducolite,  238 
Gmelinite,  115 
Gokumite,  238 
GoW,  192 

hexahedral,  192 

native,  192 
Gray  antimony,  211 

copper,  205 

oxide  of  manganese,  183 
Green  carbonate  of  copper,  88 

diallage,  124 

iron  earth,  89 

earth,  95 

vitriol,  51 

Habroneme  malachite,  87; 
prismatic,  87 
Halloyite,  238 
Hard  cobalt-pyrites,  238 
Harmotome,  109 
Hatchetine,  238 
Hauyine,  134 
Wedyphane,  239 
Xthoirope,  150 
"  Ivin,  158 
lerderite,  .239 
lerrenite,  239 
lerschelite,  239 
Hemi-prismatic  natron-salt,  42 

habroneme  malachite,  8$ 
schiller-spar,  101 
kouphone-spar,  113 
augite-spar,  124 
lead-baryte,  76 
leulandUe,  113 
fexahedral  corneous  silver,  82 

lirocone  malachite,  84 
olivenite,  84 
pearl  kerate,  82 
rock-salt,  44 
kouphone-spar,  109 
zeolite,  109 
tellurium,  183 
silver,  191 
silver-glance,  207 
gold,  192 


294 


INDEX. 


Hexakedral  cobalt-pyrites,  199 
iron-pyrites,  199 
lead-glance,  208 
galena,  208 
glance-blende,  218 

Hisingeritc,  239 

Hop  tile,  i  65 

Hornblende,  124 

Horn  silver,  82 

Humboldtine,  240 

Humile,  240 

Hyacinth,  163 

of  compostella,  151 

Hyalite,  151 

Hydro-carbon,  240 

Hydrophane,  151 

Hydrous  phosphate  of  copper,  87 
oxide  of  iron,  179 

Hydro -silicile,  240 

Hydrolite,  115 

Ice-spar,  120  s 
Ichthyophthalmile,  114 
-  Idocrase,  157 
Jndianitc,  130 
Indicolite,  156 
Ilmcnile,  231 
Indivisible  uranium,  171 
Iodide  of  mercury,  241 
Jo/tie,  148 
Iridium,  194 
Irid-osmium,  241 
Iron- ore,  177 
/ron  sinter,  241 
Jro;i  pyrites,  199 
(in  part.)  200 
prismatic,  200 

Jar  goon,  163 
Jos/jer,  149,  150 
Jeffersonite,  124 

Karphosiderite,  241 
Kerolite,  242 
Knebelile,  166 
JKbrni/e,  242 
Kupferindig,  242 
Kyanitc,  104 

prismatic,  104 

Labrador  feldspar,  119 
Latrobite,  122 
Laumonile,  110 
Lapis-lasuli,  128 
Lazulite,  128 


Lead-baryte,  74 

arseniate  of,  75 

carbonate  of,  74 

new  ore  of,  80 

spar,  75 
LeeZi/«,  242 
Levyne,  116 
Lievrite,  181 
Ligurile,  166 
Lime-stone,  60 
Lime-haloide,  59 
Liquid  muriatic  acid,  40 

sulphuric  acid,  40 
Lirocone  malachite,  84 

prismatic,  84 
Lithomarge,  255 
Lydian  stone,  150 

Macrotypous  parachrose-bary'te,  68 
Magnesia,  hydrate  of,  99 
Magr,e,sian  limestone,  62 
Magnesite,  65 
Malachite,  83,88 
Magnetic  iron-pyrites,  201 

pyrites,  201 
Manganese-spar,  136 

bi-silicate  of,  137 
^    silicate  of,  138 

silicious  oxide  of,  136 
Manganese-ore,  181 

uncleavable,  182 
gray  oxide  of,  1S& 
phosphate  of,    185 
Manganese  glance,  209 

sulphuret  of,  20& 
Manganesian  garnet,  160 
Margarite,  98 
Jtfar/,  61 
Marmolile,  242 
Mars  ft- gas,  37 
Mascagnin,  48 
Melanite,  159 
MellilUe,  167 
Melaue-gltoa.ee,  212 
Melichr one-resin,  224 
Meionite,  121 
JWeso/e,  116 
Mercury,  190 

fluid,  190 
dodecahedral,  190 
Mesotype,  111 
Meteoric  water,  39 
Jtfico,  91,  97 
Mineral-resin,  225 

yellow,  225 
black,  225 


INDEX. 


295 


Mineral  oil,  225 

pitch,  225 
coal,  227 

bituminous,  227 
non-bituminous,  228 
Mineral  hydro-carbon,  243 
Mohrite,  243 
Molybdate  of  lead,  77 

silver,  243 

Molybdena-glance,  209 
Molybdena-silver,  215 
Molybdic  silver,  215 
Monazile,  243 
Monticellite,  243 
Monophane,  243 
Mountain  soap,  255 
Murchisonite,  244 
Muriate  of  ammonia,  46 
copper,  88 
mercury,  83 
silver,  82 
soda,  44 

Muriatic  acid,  40 
Murio- carbonate  of  lead,  79 

Nacrite,  96 

Native  antimony,  188 

amalgam,  190 

bismuth,   189 

copper,  194 

gold,   192 

lead,  195 

iron,  193 

nickel,  216 

palladium,  195 

platina,  192 

quicksilver,  190 

silver,  191 

tellurium,  188 

soda  alum,  47 
Natron-salt,  42 
Needle-ofe,  216 
Nephrite,  135, 
Nitre-salt,  43 
Nitrate  oflime,  50 
Nickeliferous  gray  antimony,  204 
Nickel.glance,  244 
Nontronite,  244 

Oblique-edged  augite,  123 
Oblique   prismatic    arseniate    of 

copper,  90 
Octahedral  alum,  47 

alum-salt,  47 
ammoniac-salt,  47 
bismuth,  189 
copper.ore,  171,  194 


Octahedral  chrome-ore,  176 
iron-ore,  177 
cobalt  pyrites,  197 
copper  pyrites,  202 
corundum,  142 
diamond,  145 
iron,  193 
sal-ammoniac,  46 
Okenite,  244 
Oligoklase,  244 
Otivine,  154 
Oolite,  61 
Opal,  151 
Ore,   168 
Ortliiie,  185 
Orthoklase-haloidej  65 
Osm  elite,  244 
Ostranite,  244 
Oxidulatedlron,   177 
Oxahevrite,  244 
Oxide  of  antimony,  81 
tin,    172 
manganese,  182 
gray,  183 
Palladium,  195 
Parachrose-boryte,  67 
Paratomous  augite-spar,  123 
hal-baryte,  70 
kouphone-spar,  109 
lime-haloide,  64 
Pearl-kerale,  82,  98 
hexahedral,  82 
pyramidal,  83 
PearZmica,  98 
Pectrlspar,  62 
Pearlstone,  152 
Peastone,  61 
Pedantic,  245 
Pektolite,  245 
Periklin,  245 
Peritomous  hal-baryte,  70 
lead-baryte,  80 
ruby-blende,  222 
titanium  ore,  169 
Petaline  spar,  117 
Pefalite,  117 
Peirosilex,  245 
Pharmacolile,  66 
Phastin,  245 

Phosphate  of  copper,  85,  87 
hydrous,  85 
iron,  94 
lead,  75 
lime,  57 
manganese,  185 
uranium,  92 
Prhenile}  105 


296 


INDEX. 


Picrolite,  246 

Picrosmine,  246 

Pinguile,  246 

Pinite,  246 

Pitch-blende,  174 

Pitch-ore,  174 

Pitchstone,  152 

Plasma,  150 

Platina,  192 

Pleonaste,  141 

Plombgomme,  80 

Plumbago,  95 

Plumbo-cupriferous    sulphuret    < 
bismuth,  216 

Polishing  slate,  256 

Polyhasite,  247 

Polymignite,  247 

Polyspharite,  247 

Poonhalite,  247 

Potstone,  96 

Prenite,  105 

Prismatic  andalusite,  140 
antimony,  189 
antimony-baryte,  81 

glance,  205, 21 
arsenical-pyrites,  197 
atacamite,  88 
augite-spar,  127 
axinite,  153 
azure-malachite,  86 
azure-spar,  128 
bismuth-glance,  210 
blue-iron,  94 
boracic-acid,  41 
borax-salt,  45 
brythene-salt,  48 
chrysolite,  154 
cobalt-mica,  93 
copper-mica,  91 
copper-glance,  206 
corundum,  144 
cryone-haloide,  55 
datolite,  106 
disthene-spar,  104 
dystome-spar,  106 
emerald,  147 
emerald-malachite, 
epsom-salt,  45 
euchlore-mica,  92 
feldspar,  118 
fluor-haloide,  59 
gadolinite,  164 
garnet,  162 
glauber-salt,  42 
gypsum-haloide,  54 
gypsum,  54 


Prismatic  habroneme-malachite, 
hal-baryte,  72          [87 
baryte/72 
iron-mica,  94 
iron-ore,  179 
iron-pyrites,  200 
kouphone-spar,  109 
kyanite,  104 
lead-spar,  76 
lead-baryte,  77 
lime-haloide,  59 
Urocone-malachite,  84 
r  ^       malachite,  86 

manganese-blende,  218 
manganese-ore,  248 
melane  glance,  212 
natron-salt, 
nickel-pyrites,  185 
nitre-salt,  43 
olive-malachite,  85 
olivenite,  88 
petaline-spar,  117 
purple-blende,  220 
pyrites,  195 
quartz,  148 
red-cobalt,   93 
scheelium-ore,  173 
schiller-spar,  103 
spodumene,  105 
sulphur,  224 
talc-mica,  95 
tantalum-ore,  174 
tellurium-glance,  209 
titanium-ore,  168 
topaz,   146 
triphane-spar,  105 
vitriol-salt,  52 
wavelline-haloide,64 
wolfram,  172 
zinc-baryte,  68 
zinc-ore,  170 
zeolite,  110 

nrismatoidal  antimony-glance,21i 
augite-spar,"  126 
azure-spar,  129 
bismuth-glance,  247 
copper-glance,  205 
garnet,  162 
gypsum-haloide,  53 
hal-baryte,  73 
kouphone-spar,  112 
manganese-ore,  183 
orthoklase-haloide,  65, 
schiller-spar,  102 
sulphur,  223 
zeolite,  112, 113 


INDEX. 


Prismato -pyramidal  feldspar,  121 
titanium,  169 
rhomboidal  ruby 
blende,  222 
Pumice,  152 

Pure  atmospheric  gas,  37 
meteoric  water,  38 
Purple-blende,  220 
copper,  202 
Pycnite,  146 
Pyrallolite,  247 
Pyramidal  copper-pyrites,  202 
euchlore-mica,  92 
feldspar,  121 
garnet,   157 
honey-stone  224 
kouphone-spar,  113 
lead-baryte,  77 
lead-spar,  77 
manganese-ore,  181 
melichrone-resin,  224 
pearl-kerate,  83 
scheelium-baryte,  70 
tin-ore,  172 
titanium-ore,  170 
vitriol,  52 
zeolite,  129 
zircon,  162 
Pyrites,  195 

cellular,  201      .',  ." 
cockscomb,  201 
hepatic,  201 
magnetic,  201 
radiated,  201 
spear,  201 
uranite,  201 
Pyrope,  159 
Pyrothite,  248 
Pyrosmalite,  100 
Pyromorphite,  248 
Pyroxene,  123 

Quartz,  148 

common,  150 

empyrodox,  152 

prismatic,  148 

rhombohedral,  149 

rose,  150 

uncleavable,  150 
Quicksilver,  native,  190 

Radiated  acicular  olivenite,  90 
Radiolite,  248 
Realgar,  223 
Red  antimony,  220 
silver,  221 


Red  silver,  dark,  222 

vitriol,  52 
Resin,  224 
Retinasphalt,  226 
Retinite,  226 
Rhalizite,  104 

Right-prismatic  arseniate  of  cop- 
per, 85 
Rhomboidal  vitriol,  51 

pearl-mica,  98 

Rhombohedral  alum-haloide,  56 
antimony,  188 
apatite,  57 
corundum,  142 
calamine,  69 
emerald,  147 
emerald-malachite, 
87 

euchlore-mica,  91 
feldspar,  118 
,fluor-haloide,  57 
graphite-mica,  95 
iron-ore,  179 
iron-pyrites,  201 
kouphone-spar,  110 
Jead-baryte,  75 
lime-haloide,  60 
rnolybdena-glance, 
'  [209 

pearl-mica^ 
quartz,  149 
ruby-blende,  221 
talc-mica,  97 
tourmaline,  155 
zinc-baryte,  69 
rhomb-spai',  62 
crystal,  150 
Rock-milk,  61 
salt,  44 
Roestone,  61 
Rose-quarts,  150 
Roselite,  66 
Ruby,  141 
Ruby -blende,  221 

hemi-prismatic,  222 
peritomous,  222 
prismato-rhomboidal,  222 
rhombohedral.  221 
rhomboidal,  221 
silver,  221 

Sahlite,  123 
Salammonia,  46 
Salt,  42 
Saphirin,  249 
Sapparite,  248 


298  INDEX. 


Sapphire,  143 

oriental,  143 
Sarcolite,   117 
Sassoline,  41 
Salin-sjyar,  61 
Sausurite,  135 
Scaly-talc,  96 
Scapolite,  121 
Schalstein,  127 
Scheelium-baryie,  70 

ore,  172 

Schiller-spar,  100 
Scfcorf,  156 
Scholezite,  112 
Scordite,  90 
Seleniuret  of  lead  &  mercury,  249 
of  copper,  217 
of  lead  and  cobalt,  249 

copper,  249 
Semi-opal,  151 
Serpentine,  249 

Scsquisilicate  of  manganese,  139 
£/m/e,  254 

Silicate  of  manganese,  138 
Siliceous  oxide  of  zinc,  68 
Sillimanile,  250 
Silver,  191 
Silver-glance,  207 
Sinter,  siliceous,  151 
Slate,  253 
Smaragdile,  124 
Soda,  42 
Sodalite,  108 
Somervillite,  136 
Sommite,  118 
Sordawalite,  250 
tfjpar,  100 
Spathoseiron,  67 
Sparry-iron,  67 
Sph&rulite,  167 
Sphene,  168 
SpineUe,  141 
Spinellane,  167     %h 
Spodumene,  105 
Staphyline-malachile,  83 
Staurotide,  162 
SUrnbergite,  250 
Steatitic  serpentine,  96 
Stilbite,  112 
Stilpnosiderile,  186 
.   Strait-edged  augite,  124 
Stromnite,  74 
Strontian,  70 
Sulphate  of  alumine,  48 
Succinite,  160 
Sub-phosphate  of  alumine,  64 


ub-sulphate  of  uranium,  53 
ulphate  of  ammonia,  46 

baryles,  72 

eobalt,  52 

copper,  51 

iron,  51 

lime,  53 

lead, 77 

magnesia,  45 

magnesia  and  soda,  491 

potash,  49  4 

soda,  42 

strontia,  73 

uraneum,  53 

zinc,  52  i 
Sulphato-carbonate  of  lead,  78 
Sulphato-tri-carbonate  of  lead,  78 
Sulphur,  223 


sulphuretted  hydrogen  gas,  37 
lulphuret  of  antimony,  211 

bismuth,  210 

cobalt,  203 

copper,  206 

lead,  208 

manganese,  218 

mercury,  222 

molybdena,'  209 

silver,  207 

silver  &,  antimony, 
213 

silver  &  copper,  213 


zinc,  219 
Sulphuric  acid,  40 
liquid,  40 


[250 


Tabular-spar,  127 
Talc,  95 
Talc-mica,  95 
Tantalum-ore,  174 
Tautolite,  251 
Telluric  bismuth,  251 
Tellurium,  209 
Tellurium-glance,  209 
Tennanlite,  217 
Tephroite,  251 
Tesseralkies,  251 
Tetrahedral  boracite,  155 

copper-glance,  205 

garnet,  158 
Thenardifc,  251 
Thomsonite,  117 
T/iorr/e,  251 
T/iuMe,  136 
Tile-ore,  172 
Tin-ore,  172 
Tin-pyrites,  217 


IiNDEX. 


299 


Titanile,  169 

Titanitic-iron,  177 

Titanium-ore,  168 

Topaz,  146         / ' 

Topasolite,  160 

Tourmaline,  155 

Trapezoidal  kouphone-spar,  107 

Tremolite,  126 

Tripoli,  256 

Triphanc,  105 

Triphane-spar,  105 

Tri-prismatic  lead-spar,  77 

TH/7/e  sulphuretj  206 

Tii/a,  61 

Tungslate  of  iron,  173 

lead,  81 

lime,  70 
Tungsten,  173 
Turnerite,  25 
Turquoise,  132 

l/wt&er,  256 

Uudeavable  cerium-ore,  175 

manganese  ore,  182 

quartz,  151 

staphyline  malachite 

uranium-ore,  174   [83 
Uranium-ore,  174 

Vanadiale  of  lead,  81 
Vauquelinite,  91 
Velvet  blue  copper,  251 

Fignite,  252 


Vitreous  copper,  206 
Vitriol-salt,  51 
Vivianite,  94 

Wagnerite,  252 
Wavellite,  64 
Wavelline-haloide,  64 
fTfl/er,  39 
»%ef  slate,  257 
WP7ii/e  antimony,  81 

vitriol,  51 
WillemHe,  252 
Withamite,  131 
WWram,  173 
Wood-opal,  151 

Fe//ow;  earth,  257 

gold-glance,  218 
mineral-resin,  225 
orpiment,  223 
tellurium,  218 

Fem/e,  181 

Yttro-cerile,  252 


Zeagonile,  168 
Zeolite,  111 
Zinc-baryte,  68 
Zinc-ore,  170 
Zinkenite,  252 
Zircon,  162 
Zoisite,  127 
Zurlite,  252 


8, 
36, 
109, 
115, 
120, 
126, 


Error.  Correction, 

17  from  the  bottom,  planer,  plane. 

9,  light,  eight. 

—  Marsh-gas,  Hydrogen-gas. 

Fig.  2  misplaced  and  the  proper  Fig.  omitted. 

4,  talc,  silica. 

9,  here,  hence, 

passage  in  the  parenthesis  should  be  expunged. 


149,  Fig.-l,  should  be  considered  as  half  turned  round. 

274,    16th  line  from  top,  longitudinally  should  be  transversely. 


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